Editing Tilde (section)

==Usage==
===Common use in English<span class="anchor" id="Common use"></span>===
<!-- Advice to editors: this section is about use in English. Uses in other languages (e.g, Japanese) and specialist uses (e.g., Computing, Mathematics) go in those sections, not here. -->
The [[English language]] does not use the tilde as a diacritic, though it is used in some [[loanword]]s. The standalone form of the symbol is used more widely. Informally,<ref name=wolfram_tilde /> it means [[approximation|"approximately"]], "about", or "around", such as "~30 minutes before", meaning "''approximately'' 30 minutes before".<ref name="bymath1"/><ref>{{cite web|url=https://www.microsoft.com/typography/developers/fdsspec/maths.aspx|title=Character design standards – Maths|website=[[Microsoft]]}}</ref> It may also mean "similar to",<ref name="htmlhelp1">{{cite web| first =Liam | last = Quinn |url=http://htmlhelp.com/reference/html40/entities/symbols.html |title=HTML 4.0 Entities for Symbols and Greek Letters |publisher=HTML help |access-date=11 November 2011}}</ref> including "of the same [[order of magnitude]] as",<ref name=wolfram_tilde>{{cite web|url=http://mathworld.wolfram.com/Tilde.html | publisher = Wolfram/MathWorld | title = Tilde |date=3 November 2011 |access-date=11 November 2011}}</ref> such as "{{math |{{mvar |x}} ~ {{mvar|y}}}}" meaning that {{mvar|x}} and {{mvar|y}} are of the same order of magnitude. Another approximation symbol is the [[approximation#Mathematics|double tilde]] {{char|≈}}, meaning "approximately/almost equal to".<ref name="bymath1" /><ref name="htmlhelp1"/><ref>{{cite web |url=http://www.solving-math-problems.com/math-symbols-approximately-equal.html |title=Math Symbols... Those Most Valuable and Important: Approximately Equal Symbol |publisher=Solving Math problems |date=20 September 2010 |access-date=11 November 2011 |archive-date=9 November 2011 |archive-url=https://web.archive.org/web/20111109213922/http://www.solving-math-problems.com/math-symbols-approximately-equal.html |url-status=usurped }}</ref> The tilde is also used to indicate [[congruence (geometry)|congruence]] of shapes by placing it over an {{char|1==}} symbol, thus {{char|≅}}.

In more recent digital usage, tildes on either side of a word or phrase have sometimes come to convey a particular tone that "let[s] the enclosed words perform both sincerity and irony", which can pre-emptively defuse a negative reaction.<ref name=Bernstein>{{cite web |last1=Bernstein |first1=Joseph |title=The Hidden Language of The ~Tilde~ |url=https://www.buzzfeednews.com/article/josephbernstein/the-hidden-language-of-the-tilde |website=[[BuzzFeed News]] |date=5 January 2015 |language=en}}</ref> For example, [[BuzzFeed News|BuzzFeed]] journalist Joseph Bernstein interprets the tildes in the following [[Twitter#Tweets|tweet]]: 
:"in the ~ spirit of the season ~ will now link to some of the (imho) #Bestof2014 sports reads. if you hate nice things, mute that hashtag."
as a way of making it clear that both the author and reader are aware that the enclosed phrase – "spirit of the season" – "is cliche and we know this quality is beneath our author, and we don't want you to think our author is a cliche person generally".<ref name=Bernstein />{{efn|See also [[Air quotes]].}}

Among other uses, the symbol has been used on [[social media]] to [[Irony punctuation|indicate sarcasm]].<ref>{{cite web |title=The Internet Tilde Perfectly Conveys Something We Don't Have the Words to Explain |author= Jess Kimball Leslie | date=June 5, 2017 |website=The Cut |url=https://www.thecut.com/article/why-the-internet-tilde-is-our-most-perfect-tool-for-snark.html}}</ref> It may also be used online, especially in informal writing such as [[fan fiction|fanfiction]], to convey a cutesy, playful, or flirtatious tone.<ref>{{cite web |title=What Are Tildes ( ~ ) And How Do You Use Them? | date=April 12, 2022 |website=Thesaurus.com |url=https://www.thesaurus.com/e/grammar/tildes/}}</ref>
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===Diacritical use===
In some languages, the tilde is a [[diacritic]] mark placed over a [[Letter (alphabet)|letter]] to indicate a change in its pronunciation:

====Pitch====
The tilde was firstly used in the [[Greek diacritics|polytonic orthography]] of [[Ancient Greek]], as a variant of the [[circumflex]], representing a rise in [[pitch accent|pitch]] followed by a return to standard pitch.<ref>{{Cite book |last=Peek |first=Philip S. |url=https://books.openbookpublishers.com/10.11647/obp.0264/ch3.xhtml |title=Ancient Greek I: A 21st Century Approach; Module 3 - Accents and Accenting Verbs I |date=2021-10-19 |publisher=Open Book Publishers |isbn=978-1-80064-655-1 |pages=19–26 |doi=10.11647/OBP.0264.03 |doi-access=free |oclc=1277513901}}</ref>

====Abbreviation====
[[File:Hic Fabricatur Naves.jpg|right|thumb|''[[Carta marina]]'' showing Finnish economy, with the captions {{lang|la|Hic fabricantur naves}} and {{lang|la|Hic fabricantur [[Bombard (weapon)|bombarde]]}} abbreviated]]
Later, it was used to make [[scribal abbreviation|abbreviations]] in medieval [[Latin language|Latin]] documents. When an {{angle bracket|n}} or {{angle bracket|m}} followed a vowel, it was often omitted, and a tilde (physically, a small {{angle bracket|N}}) was placed over the preceding vowel to indicate the missing letter; this is the origin of the use of tilde to indicate nasalization (compare [[Umlaut (diacritic)#Umlaut history|the development of the umlaut]] as an abbreviation of {{angle bracket|e}}.){{Citation needed|date=December 2024|reason=Seemingly contradicted by Reimer (2015)}} A tilde represented an omitted {{angle bracket|a}} or a syllable containing it.<ref name="Reimer2015">{{Cite web |last=Reimer |first=Stephen R. |date=30 May 2015 |title=IV.vi. Paleography: Scribal Abbreviations |url=https://sites.ualberta.ca/~sreimer/ms-course/course/abbrevtn.htm |archive-url=https://web.archive.org/web/20241129100307/https://sites.ualberta.ca/~sreimer/ms-course/course/abbrevtn.htm |archive-date=2024-11-29 |access-date=2024-12-05 |website=Manuscript Studies: Medieval and Early Modern}}</ref> The practice of using the tilde over a vowel to indicate omission of an {{angle bracket|n}} or {{angle bracket|m}} continued in printed books in [[French language|French]] as a means of reducing text length until the 17th century. It was also used in [[Portuguese language|Portuguese]] and [[Spanish language|Spanish]].{{Citation needed|date=October 2024}}

The tilde was also used occasionally to make other abbreviations, such as over the letter {{angle bracket|q}}, making {{char|q̃}}, [[wikt:q̃|to signify the word ''que'']] ("that"){{Citation needed|date=December 2024|reason=Seemingly contradicted by Reimer (2015)}}. It also appears for ''qua'' and together with the letter {{angle bracket|p}} to form {{char|p̃}} for ''pra''.<ref name="Reimer2015" />

====Nasalization====
It is also as a small {{angle bracket|n}} that the tilde originated when written above other letters, marking a [[Latin language|Latin]] {{angle bracket|n}} which had been [[elision|elided]] in old Galician-Portuguese. In modern [[Portuguese language|Portuguese]] it indicates [[nasalization]] of the base vowel: {{lang|pt|mão}} "hand", from Lat. ''manu-''; {{lang|pt|razões}} "reasons", from Lat. {{lang|la|rationes}}.{{Citation needed|date=October 2024}} This usage has been adopted in the orthographies of several [[Indigenous languages of the Americas|native languages of South America]], such as [[Guarani language|Guarani]] and [[Nheengatu language|Nheengatu]], as well as in the [[International Phonetic Alphabet]] (IPA) and many other phonetic alphabets. For example, {{IPA|[ljɔ̃]}} is the IPA transcription of the pronunciation of the French place-name ''[[Lyon]]''.

In [[Breton language|Breton]], the symbol {{angle bracket|ñ}} after a vowel means that the letter {{angle bracket|n}} serves only to give the vowel a nasalised pronunciation, without being itself pronounced, as it normally is. For example, {{angle bracket|an}} gives the pronunciation {{IPA|[ãn]}} whereas {{angle bracket|añ}} gives {{IPA|[ã]}}.

In the [[Deutsche Morgenländische Gesellschaft|DMG]] romanization of [[Tunisian Arabic]], the tilde is used for nasal vowels õ and ṏ.

====Palatal n====
{{main|Ñ}}
The tilded {{angle bracket|n}} ({{angle bracket|ñ}}, {{angle bracket|Ñ}}) developed from the digraph {{angle bracket|nn}} in Spanish. In this language, {{angle bracket|ñ}} is considered a separate letter called ''[[Ñ|eñe]]'' ({{IPA|es|ˈeɲe|IPA}}), rather than a letter-diacritic combination; it is placed in Spanish dictionaries between the letters {{angle bracket|n}} and {{angle bracket|o}}. In Spanish, the word ''tilde'' actually refers to diacritics in general, e.g. the acute accent in ''José'',<ref>{{cite book |title=Ortografía de la lengua española |year=2010 |publisher=Real Academia Española |location=Madrid |isbn=978-84-670-3426-4 |page=279 }}</ref> while the diacritic in {{angle bracket|ñ}} is called "virgulilla" ({{IPA|es|birɣuˈliʝa|IPA}}) ([[yeísta]]) or ({{IPA|es|birɣuˈliʎa|IPA}}) (non-yeísta).<ref>{{Cite web |url=http://lema.rae.es/drae/?val=virgulilla |title=Lema en la RAE |publisher=[[Real Academia Española]] |access-date=10 October 2015}}</ref> Current languages in which the tilded {{angle bracket|n}} ({{angle bracket|ñ}}) is used for the [[palatal nasal]] consonant {{IPA|/ɲ/}} include
{{div col|colwidth=8em}}
* [[Asturian language|Asturian]]
* [[Aymara language|Aymara]]
* [[Basque language|Basque]]
* [[Chamorro language|Chamorro]]
* [[Filipino language|Filipino]]
* [[Galician language|Galician]]
* [[Guaraní language|Guaraní]]
* [[Iñupiaq language|Iñupiaq]]
* [[Mapudungun]]
* [[Papiamento]]
* [[Quechua languages|Quechua]]
* [[Spanish language|Spanish]]
* [[Tetum language|Tetum]]
* [[Wolof language|Wolof]]
{{div col end}}

====Tone====
In [[Vietnamese language|Vietnamese]], a tilde over a vowel represents a creaky rising [[tone (linguistics)|tone]] (''ngã''). Letters with the tilde are not considered separate letters of the [[Vietnamese alphabet]].

====International Phonetic Alphabet====
{{uncited section|date=June 2024}}
In [[phonetics]], a tilde is used as a [[IPA diacritics|diacritic that is placed]] above a letter, below it or [[superimpose]]d onto the middle of it:

* A tilde above a letter indicates [[nasalization]], e.g. {{IPA|[ã], [ṽ]}}.
* A tilde superimposed onto the middle of a letter indicates [[velarization]] or [[pharyngealization]], e.g. {{IPA|[ɫ], [z̴]}}. If no precomposed [[Unicode]] character exists, the Unicode character {{unichar|0334| COMBINING TILDE OVERLAY|cwith=◌}} can be used to generate one.
* A tilde below a letter indicates [[Creaky voice|laryngealisation]], e.g. {{IPA|[d̰]}}. If no precomposed Unicode character exists, the Unicode character {{unichar|0330| COMBINING TILDE BELOW|cwith=◌}} can be used to generate one.

A tilde between two [[phoneme]]s indicates optionality, or "alternates with". E.g. {{angbr IPA|ɕ ~ ʃ}} could indicate that the sounds may alternate depending on context ([[free variation]]), or that they vary based on region or speaker, or some other variation.

====Letter extension====
In [[Estonian language|Estonian]], the symbol {{angle bracket|õ}} stands for the [[close-mid back unrounded vowel]], and it is considered an independent letter.

====Other uses====
Some languages and alphabets use the tilde for other purposes, such as:
* [[Arabic script]]: A symbol resembling the tilde ({{unichar|0653|ARABIC MADDAH ABOVE|cwith=ـ|nlink=Arabic diacritics#Maddah}}) is used over the letter {{angle bracket|ا}} ({{IPA|/a/}}) to become <big>{{angle bracket|[[آ]]}}</big>, denoting a long {{IPA|/ʔaː/}} sound.
* [[Guaraní language|Guaraní]]: The tilded {{angle bracket|[[G̃]]}} (note that {{angle bracket|G/g}} with tilde is not available as a precomposed glyph in [[Unicode]]) stands for the [[velar nasal]] consonant. Also, the tilded {{angle bracket|y}} ({{angle bracket|Ỹ}}) stands for the nasalized upper central rounded vowel {{IPA|[ɨ̃]}}. [[Munduruku language|Munduruku]], Parintintín, and two older spellings of Filipino words also use {{angle bracket|g̃}}.
* [[Syriac script]]: A tilde (~) under the letter ''[[Kaph]]'' represents a {{IPA|[t͡ʃ]}} sound, transliterated as ''ch'' or ''č''.<ref>[[Eberhard Nestle|Nestle, Eberhard]] (1888). ''Syrische Grammatik mit Litteratur, Chrestomathie und Glossar''. Berlin: H. Reuther's Verlagsbuchhandlung. [translated to English as ''Syriac grammar with bibliography, chrestomathy and glossary'', by R. S. Kennedy. London: Williams & Norgate 1889. p. 5].</ref>
* [[Estonian phonology|Estonian]] and [[Võro language|Võro]] use the tilde above the letter o ('''õ''') to indicate the vowel {{IPA|[ɤ]}}, a rare sound among languages.
* [[Unicode]] has a [[combining character|combining]] vertical tilde character: {{unichar|033E|COMBINING VERTICAL TILDE|cwith=◌}}. It is used to indicate [[tone accent|middle tone]] in linguistic transcription of certain dialects of the [[Lithuanian language]],<ref>Lithuanian Standards Board (LST), [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n2597.pdf proposal for a zigzag diacritic]</ref> and was also used historically in the letter [[х̾]], which was part of the [[Cyrillization of Polish under the Russian Empire|Polish Cyrillic alphabet]] of the late 19th century.
* [[Resurrección María de Azkue]]'s 1906 Basque dictionary used an idiosyncratic spelling including {{anglebracket|[[ã]] [[d̃]] [[ẽ]] [[ĩ]] [[l̃]] [[ñ]] [[õ]] [[s̃]] [[t̃]] [[ũ]] [[x̃]]}}.<ref name="Azkue">{{cite web |title=R. M. de Azkue: "Euskara-Gaztelania-Frantsesa Hiztegia" / "Diccionario Vasco-Español-Francés" online -Tutorial de uso |url=https://www.aurtenbai.eus/dok/Azkue-tutoriala_ES.pdf |publisher=Aurten Bai Fundazioa |access-date=12 February 2024 |page=6 |language=es |quote=El autor usaba fuentes propias para representar fenómenos propios de algunos de los dialectos del euskera. Estos son los caracteres especiales utilizados en el diccionario: ã d̃ ẽ ĩ l̃ ñ õ s̃ t̃ ũ x̃.}}</ref>

===Punctuation===
The tilde is used in various ways in punctuation, including:

In some languages (such as in French),{{cn|date=July 2024}} a tilde or a tilde-like [[wave dash]] (Unicode: {{unichar|301C|wave dash}}) may be used as a [[punctuation]] mark (instead of an unspaced [[hyphen]], [[en dash]] or [[em dash]]) between two [[number]]s, to indicate a [[Interval (mathematics)|range]]. Doing so avoids the risk of confusion with [[subtraction]] or a hyphenated number (such as a part number or model number). For example, "12~15" means "12 to 15", "~3" means "up to three", and "100~" means "100 and greater".{{cn|date=December 2023}} [[Languages of East Asia|East Asian languages]] almost always use this convention, but it is sometimes done for clarity in some other languages as well. [[Chinese language|Chinese]] uses the wave dash and [[Halfwidth and fullwidth forms|full-width]] em dash interchangeably for this purpose. In English, the tilde is often used to express ranges and model numbers in [[electronics]], but rarely in formal grammar or in type-set documents, as a wavy dash preceding a number sometimes represents an approximation (see below).

The '''range tilde''' is used for various purposes in [[French language|French]], but only to denote ranges of numbers (e.g., {{lang|fr|«&nbsp;21~32 degrés Celsius&nbsp;»}}" means "21 to 32 degrees Celsius"){{cn|date=May 2024}}

(The symbol {{unichar|2248}} (a [[double tilde (disambiguation)|double tilde]]) is also used in French, for example, {{lang|fr|«&nbsp;≈400 mètres&nbsp;»}} means "approximately 400 meters"{{cn|date=May 2024}}.)

==== Approximation ====
{{see also|Approximation}}
Before a number the tilde can mean 'approximately'; '~42' means 'approximately 42'.<ref>
{{Cite web | url = http://www.linfo.org/tilde.html | title = Tilde Definition | website=linfo.org | publisher = The Linux Information Project | date = 24 June 2005 | access-date= 27 January 2020}}</ref> When used with [[currency symbol]]s that precede the number (national conventions differ), the tilde precedes the symbol, thus for example '~$10' means 'about ten dollars'.<ref>{{Cite web
|url=https://english.stackexchange.com/questions/116048/using-a-tilde-with-currency |title=Using a tilde with currency|website=[[Stackexchange]]}}</ref>{{better source|reason=Not a reliable source|date=February 2024}}

The symbols <big>≈</big> (almost equal to) and <big>≅</big> (approximately equal to) are among the other [[approximation#Unicode|symbols used to express approximation]].

====Japanese====
{{further|Japanese punctuation#Wave dash}}

The {{Nihongo|'''wave dash'''|波ダッシュ|nami dasshu}} is used for various purposes in Japanese, including to denote ranges of numbers (e.g., ''5〜10'' means between 5 and 10) in place of dashes or brackets, and to indicate origin. The wave dash is also used to separate a title and a subtitle in the same line, as a [[Colon (punctuation)|colon]] is used in English.

When used in conversations via email or instant messenger it may be used as a [[sarcasm mark]] {{citation needed|date=January 2024}}.

The sign is used as a replacement for the {{transliteration|ja|[[Chōonpu|chōon]]}}, katakana character, in Japanese, extending the final syllable.


===Chinese===

[[WeChat]] users frequently replace final punctuations with tildes in messages. An analysis of such "innovative uses" of tildes found that final tildes are most used to make the message friendlier and polite. They make expressives more sincere and directives less abrupt. Less commonly, final tildes imply sounds, i.e. otomatopeas and sound extensions. This use is compared to ''sajiao'' ({{Lang-zh|s=撒娇}}), a child-like acting seen in East Asian cultures that are also vocalized by raising or extending tone.<ref>{{Cite journal |last1=Xu |first1=Huan |last2=Xia |first2=Dengshan |date=2023-09-01 |title=Digital tildes ("∼") may convey more: analyzing innovative uses of tildes in Chinese WeChat messages |journal=Language and Semiotic Studies |language=en |volume=9 |issue=3 |pages=443–460 |doi=10.1515/lass-2023-0009 |issn=2751-7160|doi-access=free }}</ref>

===Mathematics===

====As a unary operator====
A tilde in front of a single quantity can mean "approximately", "about"<ref name="bymath1">{{Cite web |title=All Elementary Mathematics – Mathematical symbols dictionary |url=http://www.bymath.com/symbols/symbols.html |publisher=Bymath |accessdate=2014-09-25 |archive-date=2 May 2015 |archive-url=https://web.archive.org/web/20150502113549/http://www.bymath.com/symbols/symbols.html |url-status=dead }}</ref> or "of the same [[order of magnitude]] as."

In written [[mathematical logic]], the tilde represents [[negation]]: "~''p''" means "not ''p''", where "''p''" is a [[proposition]]. Modern use often replaces the tilde with the negation symbol (¬) for this purpose, to avoid confusion with [[equivalence relation]]s.

====As a relational operator====

In [[mathematics]], the tilde operator (which can be represented by a tilde or the dedicated character {{unichar|223C|TILDE OPERATOR}}), sometimes called "twiddle", is often used to denote an [[equivalence relation]] between two objects. Thus "{{math|{{mvar|x}} ~ {{mvar|y}}}}" means "{{mvar|x}} is [[equivalence relation|equivalent]] to {{mvar|y}}". It is a weaker statement than stating that {{mvar|x}} [[equality (mathematics)|equals]] {{mvar|y}}. The expression "{{math|{{mvar|x}} ~ {{mvar |y}}}}" is sometimes read aloud as "{{mvar|x}} twiddles {{mvar|y}}", perhaps as an analogue to the verbal expression of "{{math |1={{mvar |x}} = {{mvar|y}}}}".<ref>{{Citation | last = Derbyshire | first = J | title = Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics | place = New York | publisher = Penguin | year = 2004 | url = http://mathworld.wolfram.com/Tilde.html}}.</ref>

The tilde can indicate approximate equality in a variety of ways. It can be used to denote the [[asymptotic analysis|asymptotic equality]] of two functions. For example, {{math|{{mvar|f}} ({{mvar|x}}) ~ {{mvar |g}}({{mvar |x}})}} means that <math>\lim_{x \to \infty} \frac{f(x)}{g(x)} = 1</math>.<ref name=wolfram_tilde />

A tilde is also used to indicate "[[Approximation|approximately]] equal to" (e.g. 1.902 ~= 2). This usage probably developed as a typed alternative to the [[:Image:Libra.svg|libra symbol]] used for the same purpose in written mathematics, which is an equal sign with the upper bar replaced by a bar with an upward hump, bump, or loop in the middle (︍︍♎&#xFE0E;) or, sometimes, a tilde (≃).{{Citation needed|date=October 2024}} The symbol "≈" is also used for this purpose.

In [[physics]] and [[astronomy]], a tilde can be used between two expressions (e.g. {{math|{{mvar|h}} ~ 10<sup>−34</sup> J s}}) to state that the two are of the same [[order of magnitude]].<ref name=wolfram_tilde />

In [[statistics]] and [[probability theory]], the tilde means "is distributed as";<ref name = wolfram_tilde /> see [[random variable]] (e.g. {{math|''X'' ~ ''B''(''n'', ''p'')}} for a [[binomial distribution]]).

A tilde can also be used to represent geometric [[Similarity (geometry)|similarity]] (e.g. {{math |∆{{mvar |ABC}} ~ ∆{{mvar|DEF}}}}, meaning [[triangle]] {{mvar|ABC}} is similar to {{mvar|DEF}}). A triple tilde ('''≋''') is often used to show [[congruence (geometry)|congruence]], an equivalence relation in geometry.{{Citation needed|date=October 2024}}

In [[graph theory]], the tilde can be used to represent adjacency between vertices. The edge <math>(x,y)</math> connects vertices <math>x</math> and <math>y</math> which can be said to be adjacent, and this adjacency can be denoted <math>x \sim y</math>.

====As a diacritic====

The symbol "<math>\tilde{f}</math>" is pronounced as "eff tilde" or, informally, as "eff twiddle".<ref>{{cite web |url=http://mathworld.wolfram.com/Tilde.html |title = Tilde |publisher = Wolfram Research |access-date = 4 June 2018}}</ref><ref>{{cite book |url=https://books.google.com/books?id=SY5fZIK63NMC&q=schlange+twiddle&pg=PA53 |title=Proceedings of the Analysis Conference, Singapore 1986 |publisher=Elsevier | year = 1988 | first1 =Stephen TL | last1 = Choy | first2 =Judith Packer | last2 = Jesudason | first3 = Peng Yee | last3 = Lee|isbn=9780080872612 }}</ref> This can be used to denote the [[Fourier transform]] of ''f'', or a [[lift (mathematics)|lift]] of ''f'', and can have a variety of other meanings depending on the context.

A tilde placed below a letter in mathematics can represent a [[Euclidean vector|vector]] quantity (e.g. <math>(x_1, x_2, x_3, \ldots, x_n) = \underset{^\sim}{\mathbf x}</math>).

In [[statistics]] and [[probability theory]], a tilde placed on top of a variable is sometimes used to represent the [[median]] of that variable; thus <math>\tilde{\mathbf y}</math> would indicate the median of the variable <math>\mathbf y</math>. A tilde over the letter n (<math>\tilde{n}</math>) is sometimes used to indicate the [[harmonic mean]].

In machine learning, a tilde may represent a candidate value for a cell state in [[Gated recurrent unit|GRUs]] or [[LSTM]] units. (e.g. c̃)

===Physics===
Often in [[physics]], one can consider an [[equilibrium solution]] to an equation, and then a perturbation to that equilibrium. For the variables in the original equation (for instance <math>X</math>) a substitution <math>X\to x+\tilde{x}</math> can be made, where <math>x</math> is the equilibrium part and <math>\tilde{x}</math> is the perturbed part.

A tilde is also used in [[particle physics]] to denote the hypothetical [[supersymmetric]] partner. For example, an [[electron]] is referred to by the letter ''e'', and its [[superpartner]] the [[selectron (particle)|selectron]] is written ''ẽ''.

In multibody mechanics, the tilde operator maps three-dimensional vectors <math>\boldsymbol{\omega}\in\mathbb{R}^3</math> to skew-symmetrical matrices <math>\tilde{\boldsymbol{\omega}}=\begin{bmatrix}0&-\omega_3& \omega_2\\ \omega_3& 0& -\omega_1\\ -\omega_2&\omega_1&0\end{bmatrix}</math> (see <ref>{{cite journal |last1=Wallrapp |title=Standardization of flexible body modeling in multibody system codes, Part I: Definition of Standard Input Data |date=1994 |volume=22 |issue=3 |pages=283–304 |doi=10.1080/08905459408905214 |journal=Mechanics of Structures and Machines}}</ref> or <ref>{{cite journal |last1=Valembois |first1=R. E. |last2=Fisette |first2=P. |last3=Samin |first3=J. C. |title=Comparison of Various Techniques for Modelling Flexible Beams in Multibody Dynamics |journal=Nonlinear Dynamics |date=1997 |volume=12 |issue=4 |pages=367–397 |doi=10.1023/A:1008204330035|bibcode=1997NonDy..12..367V |s2cid=122487067 }}</ref>).

===Economics===
For relations involving preference, [[economist]]s sometimes use the tilde to represent [[Preference (economics)#Notation|indifference]] between two or more bundles of goods. For example, to say that a consumer is indifferent between bundles ''x'' and ''y'', an economist would write ''x'' ~ ''y''.

===Electronics===
It can approximate the sine wave symbol (∿, [[Unicode|U+]]223F), which is used in [[electronics]] to indicate [[alternating current]], in place of +, −, or ⎓ for [[direct current]].

===Linguistics===
The tilde may indicate alternating [[allomorph]]s or [[Morphophonology|morphological alternation]], as in {{IPA|//ˈniː~ɛl+t//}} for ''kneel~knelt'' (the [[plus sign#Other uses|plus sign]] '+' indicates a morpheme boundary).<ref>Collinge (2002) ''An Encyclopedia of Language'', §4.2.</ref><ref>{{Cite book | last=Hayes | first=Bruce | author-link=Bruce Hayes (linguist) | title=Introductory Phonology | publisher=John Wiley & Sons | date=2011 | isbn=9781444360134 | pages=87–88 }}</ref>

The tilde may represent some sort of phonetic or phonemic variation between two sounds, which might be [[allophone]]s or in [[free variation]]. For example, {{IPA|[χ ~ x]}} can represent "either {{IPA|[χ]}} or {{IPA|[x]}}".

In [[formal semantics (linguistics)|formal semantics]], it is also used as a notation for the ''[[squiggle operator]]'' which plays a key role in many theories of [[focus (linguistics)|focus]].<ref>{{cite book |last=Buring |first=Daniel |date=2016 |title=Intonation and Meaning |doi=10.1093/acprof:oso/9780199226269.003.0003 |publisher=Oxford University Press |pages=36–41 |isbn=978-0-19-922627-6}}</ref>

In [[interlinear gloss]], a tilde sets off an element added to a word by [[reduplication]]; were a hyphen or double hyphen used instead, confusion would arise because that element would be notated  in the same way as an independent morpheme requiring an independent gloss.

===Computing===

[[Computer programmers]] use the tilde in various ways and sometimes call the symbol (as opposed to the diacritic) a '''squiggle''', '''squiggly''', '''swiggle''', or '''twiddle'''. According to the [[Jargon File]], other synonyms sometimes used in programming include '''not''', '''approx''', '''wiggle''', '''enyay''' (after ''[[ñ|eñe]]'') and (humorously) '''sqiggle''' {{IPAc-en|ˈ|s|k|ɪ|ɡ|əl}}.<ref name=":0">{{Cite web |date=2012-01-05 |title=Jargon File 5.0.1 |url=http://cosman246.com/jargon.html |url-status=usurped |archive-url=https://web.archive.org/web/20130827121341/http://cosman246.com/jargon.html |archive-date=2013-08-27}}</ref>

==== Directories and URLs ====
On [[Unix]]-like [[operating system]]s (including [[AIX]], [[BSD]], [[Linux]] and [[macOS]]), tilde normally indicates the current user's [[home directory]]. For example, if the current user's home directory is {{mono|/home/user}}, then the command {{mono|cd ~}} is equivalent to {{mono|cd /home/user}}, {{mono|cd $HOME}}, or {{mono|cd}}.<ref name=":0" /> This convention derives from the [[Lear-Siegler]] [[ADM-3A]] terminal in common use during the 1970s, which happened to have the tilde symbol and the word "Home" (for moving the cursor to the upper left) on the same key.<ref>{{cite book |last=Hogan |first=Brian |date=2019 |title=Small, Sharp Software Tools |publisher=Pragmatic Programmers |page=3 |isbn=978-1-68050-296-1 }}</ref> When prepended to a particular username, the tilde indicates that user's home directory (e.g., {{mono|~janedoe}} for the home directory of user {{mono|janedoe}}, such as {{mono|/home/janedoe}}).<ref>{{Citation | contribution = Tilde expansion | publisher = The GNU project | title = C Library Manual | access-date = 4 July 2010 | url = https://www.gnu.org/s/libc/manual/html_node/Tilde-Expansion.html}}.</ref>

Used in [[Uniform Resource Locator|URLs]] on the [[World Wide Web]], it often denotes a personal website on a [[Unix]]-based server. For example, {{mono|<nowiki>http://www.example.com/~johndoe/</nowiki>}} might be the personal website of John Doe. This mimics the Unix shell usage of the tilde. However, when accessed from the web, file access is usually directed to a [[subdirectory]] in the user's home directory, such as {{mono|/home/''username''/public_html}} or {{mono|/home/''username''/www}}.<ref>{{Citation | contribution = Module mod_userdir | publisher = The Apache foundation | title = HTTP Server Documentation | edition = version 2.0 | access-date = 4 July 2010 | url = http://httpd.apache.org/docs/2.0/mod/mod_userdir.html}}.</ref>

In URLs, the characters {{mono|%7E}} (or {{mono|%7e}}) may substitute for a tilde if an input device lacks a tilde key.{{Ref RFC|3986|p=12}} Thus, {{mono|<nowiki>http://www.example.com/~johndoe/</nowiki>}} and {{mono|<nowiki>http://www.example.com/%7Ejohndoe/</nowiki>}} will behave in the same manner.

==== Computer languages ====
=====Regex=====
The tilde is used in the [[AWK]] [[programming language]] as part of the pattern match operators for [[regular expression]]s:<ref>{{cite web |title=The GNU Awk User's Guide |website=GNU Manuals Online |url=https://www.gnu.org/software/gawk/manual/html_node/Regexp-Usage.html |publisher=Free Software Foundation, Inc. |access-date=2024-10-20 |at=3.1 How to Use Regular Expressions}}</ref>
*<code>''variable'' ~ /''regex''/</code> returns true if the variable is matched.
*<code>''variable'' !~ /''regex''/</code> returns false if the variable is matched.

The operators are also used in the [[SQL]] variant of the database [[PostgreSQL]].<ref>{{cite web |title=PostgreSQL 17.0 Documentation |author=The PostgreSQL Global Development Group |date=2024-09-26 |url=https://www.postgresql.org/docs/17/index.html |access-date=2024-10-20 |at=[https://www.postgresql.org/docs/current/functions-matching.html#FUNCTIONS-POSIX-REGEXP 9.7.3.{{nbsp}}POSIX Regular Expressions]}}</ref>

A variant of this, with the plain tilde replaced with <code>=~</code>, was adopted in [[Perl]]<ref>{{cite web |title=Perl expressions: operators, precedence, string literals |website=Perldoc Browser |url=https://perldoc.perl.org/5.40.0/perlop |access-date=2024-10-20 |at=[https://perldoc.perl.org/5.40.0/perlop#Binding-Operators Binding Operators]}}</ref><!--, and this semi-standardization has led to the use of these operators in other programming languages-->. [[Ruby programming language|Ruby]] also uses this variant without the negated operator.<ref>{{cite web |title=class Regexp |work=Documentation for Ruby 3.3 |url=https://docs.ruby-lang.org/en/3.3/Regexp.html |access-date=2024-10-20}}</ref>

=====Negation=====

In [[APL (programming language)|APL]]<ref name="j303">{{cite web |title=APL2 Programming: Language Reference |publisher=[[IBM]] |url=https://www.ibm.com/downloads/cas/ZOKMYKOY |date=February 1994 |edition=2nd |access-date=2024-10-22}}</ref>{{rp|68}} and [[MATLAB]],<ref>{{cite web |title=MATLAB Operators and Special Characters - MATLAB & Simulink |website=MathWorks |url=https://www.mathworks.com/help/matlab/matlab_prog/matlab-operators-and-special-characters.html |access-date=2024-10-22}}</ref> tilde represents the monadic logical function NOT. and in APL it additionally represents the dyadic [[multiset]] function ''without'' ([[Complement (set theory)#Relative complement|set difference]]).<ref name="j303"/>{{rp|258}}

In [[C (programming language)|C]] the tilde character is used as [[bitwise NOT]] unary [[Operators in C and C++|operator]], following the notation in logic (an <code>!</code> causes a logical NOT, instead).<ref>{{cite web |title=Programming languages — C |url=https://files.lhmouse.com/standards/ISO%20C%20N2176.pdf |author=ISO/IEC |access-date=2024-10-19 |page=64 }}</ref> This is also used by many languages based on or influenced by C, such as [[C++]], [[C Sharp (programming language)|C#]], [[D programming language|D]], [[Java (programming language)|Java]], [[JavaScript]], [[Perl]], [[PHP]], and [[Python (programming language)|Python]].<ref name="rigaux">{{Cite web |title=syntax across languages (One Big Page) |url=https://rigaux.org/language-study/syntax-across-languages.html |access-date=2024-11-28 |website=rigaux.org |archive-url=https://web.archive.org/web/20240823220158/http://rigaux.org/language-study/syntax-across-languages.html |archive-date=2024-08-23}}</ref> The [[MySQL|MySQL database]] also use tilde as bitwise invert<ref>{{Cite web|url=https://dev.mysql.com/doc/refman/8.0/en/bit-functions.html#operator_bitwise-invert|title=MySQL :: Reference Manual :: Bit Functions and Operators|website=dev.mysql.com|access-date=2019-12-20}}</ref> as does Microsoft's SQL Server [[Transact-SQL|Transact-SQL (T-SQL)]] language.

======~~ cast======
<!-- This section title is linked to, so if you change the section title then please place this anchor in the page text here: {{anchor|~~ cast}} -->
[[JavaScript]] also uses tilde as bitwise NOT. Because bitwise operators work on integers, and numbers in JavaScript are 64 bit floating point numbers, the operator converts numbers to a 32-bit signed integer before it performing the negation.<ref>{{Cite web |title=JavaScript Bitwise Operations |url=https://www.w3schools.com/js/js_bitwise.asp |access-date=2024-11-28 |website=W3Schools |language=en-US |archive-url=https://web.archive.org/web/20241128173553/https://www.w3schools.com/js/js_bitwise.asp |archive-date=2024-11-28}}</ref> The conversion truncates the fractional part and most significant bits. This lets two tildes <code>~~x</code> to be used as a short syntax to cast to integer. However, it is not recommended as use for truncation. In contrast, it does not truncate BigInts, which are arbitrarily large integers.<ref>{{Cite web |date=2023-08-15 |title=Bitwise NOT (~) - JavaScript |url=https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT |access-date=2024-11-28 |website=MDN |language=en-US |archive-url=https://web.archive.org/web/20241128173342/https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT |archive-date=2024-11-28}}</ref>

=====Other uses=====

In C++<ref>{{Cite web |date=2023-12-01 |title=Destructors (C++) |url=https://learn.microsoft.com/en-us/cpp/cpp/destructors-cpp?view=msvc-170 |access-date=2024-11-28 |website=Microsoft Learn |publisher=[[Microsoft]] |language=en-us |archive-url=https://web.archive.org/web/20241128170724/https://learn.microsoft.com/en-us/cpp/cpp/destructors-cpp?view=msvc-170 |archive-date=2024-11-28}}</ref> and C#,<ref>{{Cite web |date=2023-03-14 |title=Finalizers (C# Programming Guide) |url=https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/finalizers |access-date=2024-11-28 |website=Microsoft Learn |publisher=[[Microsoft]] |language=en-us |archive-url=https://web.archive.org/web/20241117135601/https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/finalizers |archive-date=2024-11-17}}</ref> the tilde is also used as the first character in a [[Class (computer science)|class]]'s [[method (computer science)|method]] name (where the rest of the name must be the same name as the class) to indicate a [[destructor (computer science)|destructor]] – a special method which is called at the end of the [[Object lifetime|object's life]].

In ASP.NET applications, tilde ('~') is used as a shortcut to the root of the application's virtual directory.<ref>{{Cite web |date=2022-06-03 |title=ASP.NET Core built-in Tag Helpers |url=https://learn.microsoft.com/en-us/aspnet/core/mvc/views/tag-helpers/built-in/?view=aspnetcore-9.0 |access-date=2024-11-28 |website=Microsoft Learn |publisher=[[Microsoft]] |language=en-us |archive-url=https://web.archive.org/web/20241128180850/https://learn.microsoft.com/en-us/aspnet/core/mvc/views/tag-helpers/built-in/?view=aspnetcore-9.0 |archive-date=2024-11-28}}</ref>

In the [[Cascading Style Sheets|CSS]] stylesheet language, the tilde finds the element selected by the right-hand side that shares the parent with an element selected by the left-hand side.<ref>{{Cite web |date=2022-11-11 |title=Selectors Level 4 |url=https://www.w3.org/TR/selectors-4/ |archive-url=https://web.archive.org/web/20241122212236/https://www.w3.org/TR/selectors-4/ |archive-date=2024-11-22 |access-date=2024-11-28 |publisher=CSS Working Group |at=[https://www.w3.org/TR/selectors-4/#general-sibling-combinators 15.4. Subsequent-sibling combinator (~)] |type=W3C Working Draft}}</ref>

In the [[D programming language]], the tilde is used as bitwise not operator, [[concatenation]] operator such as those of [[Array data structure|arrays]],<ref>{{Cite web |title=Expressions |url=https://dlang.org/spec/expression.html |archive-url=https://web.archive.org/web/20241128204134/https://dlang.org/spec/expression.html |archive-date=2024-11-28 |access-date=2024-11-28 |website=dlang.org}}</ref> and to indicate an object destructor.<ref>{{Cite web |title=Structs, Unions |url=https://dlang.org/spec/struct.html |archive-url=https://web.archive.org/web/20241128210801/https://dlang.org/spec/struct.html |archive-date=2024-11-28 |access-date=2024-11-28 |website=dlang.org}}</ref><ref>{{Cite web |title=Classes |url=https://dlang.org/spec/class.html |archive-url=https://web.archive.org/web/20241128210843/https://dlang.org/spec/class.html |archive-date=2024-11-28 |access-date=2024-11-28 |website=dlang.org}}</ref> Tilde operator can be overloaded for user types,<ref>{{Cite web |title=Operator Overloading |url=https://dlang.org/spec/operatoroverloading.html |archive-url=https://web.archive.org/web/20241128204128/https://dlang.org/spec/operatoroverloading.html |archive-date=2024-11-28 |access-date=2024-11-28 |website=dlang.org}}</ref> and binary tilde operator is mostly used to merging two objects, or adding some objects to set of objects. It was introduced because plus operator can have different meaning in many situations. For example, "120" + "14" may produce "134" (addition of two numbers), "12014" (concatenation of strings), or something else.<ref>{{Cite web |title=Arrays |url=https://dlang.org/spec/arrays.html |archive-url=https://web.archive.org/web/20241128204600/https://dlang.org/spec/arrays.html |archive-date=2024-11-28 |access-date=2024-11-28 |website=dlang.org}}</ref> D disallows + operator for arrays (and strings), and provides separate operator for concatenation (similarly [[PHP]] programming language solved this problem by using dot operator for concatenation, and + for number addition, which will also work on strings containing numbers).

In [[Eiffel (programming language)|Eiffel]], the tilde is used for object comparison. If ''a'' and ''b'' denote objects, the Boolean expression ''a'' ~ ''b'' has value true if and only if these objects are equal, as defined by the applicable version of the library routine ''is_equal'', which by default denotes field-by-field object equality but can be redefined in any class to support a specific notion of equality.<ref>{{Cite web |date=June 2006 |title=Eiffel: Analysis, Design and Programming Language |url=https://www.ecma-international.org/wp-content/uploads/ECMA-367_2nd_edition_june_2006.pdf |archive-url=https://web.archive.org/web/20241128214008/https://www.ecma-international.org/wp-content/uploads/ECMA-367_2nd_edition_june_2006.pdf |archive-date=2024-11-28 |access-date=2024-11-28 |publisher=ECMA International |id=ECMA-367 |edition=2nd}}</ref>{{rp|114-115}} If ''a'' and ''b'' are references, the object equality expression ''a'' ~ ''b'' is to be contrasted with ''a'' = ''b'' which denotes reference equality. Unlike the call ''a''.''is_equal'' (''b''), the expression ''a'' ~ ''b'' is [[type safety|type-safe]] even in the presence of [[Covariance and contravariance (computer science)|covariance]].<!--{{Citation needed|date=November 2024}}-->

In the [[Groovy (programming language)|Apache Groovy programming language]] the tilde character overloaded as a bitwise binary negation operation, and as the "pattern operator" that creates a [[regular expression]] pattern object. <code>=~</code> and <code>==~</code> can in Groovy be used to match a regular expression.<ref>{{cite web|url=https://groovy-lang.org/operators.html|title=The Groovy programming language – Operators}}</ref>

In [[Haskell (programming language)|Haskell]], the tilde is used in type constraints to indicate type equality.<ref>{{Citation | url = http://www.haskell.org/haskellwiki/GHC/Type_families#Equality_constraints | title = Haskell Wiki | contribution = Type Families}}.</ref> Also, in pattern-matching, the tilde is used to indicate a lazy pattern match.<ref>{{cite web|url=http://www.haskell.org/haskellwiki/Lazy_pattern_match|title=Lazy pattern match}}</ref>

In the [[Inform]] 6 programming language, the tilde is used to indicate a quotation mark inside a quoted string. Tilde itself is created by <code>@@126</code>.
<ref>{{Cite book |last=Nelson |first=Graham |date=July 2001 |contribution=§1 Routines |contribution-url=https://www.inform-fiction.org/manual/html/s1.html |archive-url=https://web.archive.org/web/20240607185340/https://www.inform-fiction.org/manual/html/s1.html |archive-date=2024-06-07 |access-date=2024-11-28 |title=The Inform Designer's Manual |publisher=Interactive Fiction Library |isbn=0-9713119-0-0 |edition=4th}}</ref>

In "text mode" of the [[LaTeX]] typesetting language a tilde diacritic can be obtained using, e.g., <code>\~{n}</code>, yielding "ñ". A stand-alone tilde can be obtained by using <code>\textasciitilde</code> or <code>\string~</code>.
In "math mode" a tilde diacritic can be written as, e.g., <code>\tilde{x}</code>. For a wider tilde <code>\widetilde</code> can be used. The <code>\sim</code> command produce a tilde-like binary relation symbol that is often used in mathematical expressions, and the double-tilde [[≈]] is obtained with <code>\approx</code>.In both text and math mode, a tilde on its own (<code>~</code>) renders a white space with no line breaking.In both text and math mode, a tilde on its own (<code>~</code>) renders a white space with no line breaking.<ref>{{cite web |last=Doob| first=Michael|date=Jan 21, 2002 |title=A Gentle Introduction to TeX |url=https://texdoc.org/serve/gentle.pdf/0 |website=texdoc.org | page=11,12,15,32,36,37|location=Winnipeg, Manitoba |access-date=Apr 6, 2025}}</ref>  The <code>url</code> package also supports entering tildes directly, e.g., <code><nowiki>\url{http://server/~name}</nowiki></code>.{{Citation needed|date=April 2025}}
.

In [[MediaWiki]] syntax, four tildes are a shortcut for a user's signature. Three and five tildes puts the signature without timestamp and only the timestamp, respectively.<ref>{{Cite web |title=Help:Signatures |url=https://www.mediawiki.org/w/index.php?title=Help:Signatures&oldid=6657175 |date=20 July 2024 |access-date=2024-11-28 |website=MediaWiki |language=en |archive-url=https://web.archive.org/web/20241128225211/https://www.mediawiki.org/w/index.php?title=Help:Signatures&oldid=6657175 |archive-date=2024-11-28}}</ref>

In [[Common Lisp]], the tilde is used as the prefix for format specifiers in format strings.<ref>{{cite web|url=http://www.lispworks.com/documentation/HyperSpec/Body/22_c.htm |title=CLHS: Section 22.3 |publisher=Lispworks.com |date=2005-04-11 |access-date=2010-07-30}}</ref>

In [[Max/MSP]], MSP objects have names ending with a tilde. MSP objects process at the computer's sampling rate and mainly deal with sound.<ref>{{Cite web |author="Cycling '74" |title=MSP Basics Tutorial 1: Test Tone |url=https://docs.cycling74.com/learn/articles/05_mspbasicchapter01/ |archive-url=https://web.archive.org/web/20241206215808/https://docs.cycling74.com/learn/articles/05_mspbasicchapter01/ |archive-date=2024-12-06 |access-date=2024-12-06 |website=Cycling '74 Documentation |language=en}}</ref>

In [[Standard ML]], the tilde is used as the prefix for negative numbers and as the unary negation operator.<ref>{{Cite web |last=Fisher |first=Kathleen |title=Learning Standard ML |url=https://www.cs.tufts.edu/comp/105-2017f/readings/ml.html |access-date=2024-12-06 |website=www.cs.tufts.edu |at=[https://www.cs.tufts.edu/comp/105-2017f/readings/ml.html#expressions-ii-minus-signs Expressions II: Minus signs]}}</ref>

In [[OCaml]], the tilde is used to specify the label for a labeled parameter.<ref>{{Cite web |title=Labelled and Optional Arguments |url=https://ocaml.org/docs/labels |archive-url=https://web.archive.org/web/20241206214050/https://ocaml.org/docs/labels |archive-date=2024-12-06 |access-date=2024-12-06 |website=OCaml |language=en}}</ref>

In [[R (programming language)|R]], the tilde operator is used to separate the left- and right-hand sides in a model formula.<ref>[https://cran.r-project.org/doc/manuals/r-release/fullrefman.pdf The R Reference Index ]</ref>

In [[Object REXX]], the twiddle is used as a "message send" symbol. For example, <code>Employee.name~lower()</code> would cause the <code>lower()</code> method to act on the object <code>Employee</code>'s <code>name</code> attribute, returning the result of the operation. <code>~~</code> returns the object that received the method rather than the result produced. Thus, it can be used when the result need not be returned or when cascading methods are to be used. <code>team~~insert("Jane")~~insert("Joe")~~insert("Steve")</code> would send multiple concurrent <code>insert</code> messages, thus invoking the <code>insert</code> method three consecutive times on the <code>team</code> object.<ref>{{Cite web |last1=Ashley |first1=W. David |last2=Flatscher |first2=Rony G. |last3=Hessling |first3=Mark |last4=McGuire |first4=Rick |last5=Miesfeld |first5=Mark |last6=Peedin |first6=Lee |last7=Tammer |first7=Rainer |last8=Wolfers |first8=Jon |date=August 14, 2009 |title=Terms, Expressions, and Operators |url=https://www.oorexx.org/docs/rexxref/x974.htm |url-status=dead |archive-url=https://web.archive.org/web/20210116122945/https://www.oorexx.org/docs/rexxref/x974.htm |archive-date=2021-01-16 |access-date=2024-12-06 |website=Open Object Rexx™: Reference |series=Version 4.0.0 Edition}}</ref>

In [[Raku (programming language)|Raku]], a prefixing tilde [[type conversion|converts]] a value to a string. An infix tilde [[concatenate]]s strings,<ref name="rakudocs-operators">{{Cite web |date=2024-09-13 |title=Operators |url=https://docs.raku.org/language/operators |archive-url=https://web.archive.org/web/20241130145259/https://docs.raku.org/language/operators |archive-date=2024-11-30 |access-date=2024-12-06 |website=Raku documentation}}</ref> taking place of the dot operator in Perl, as the dot is used for member access instead of {{code|->}}.<ref name="rakudocs-perl">{{Cite web |date=2024-08-01 |title=Perl to Raku guide - in a nutshell |url=https://docs.raku.org/language/operators |archive-url=https://web.archive.org/web/20241203160657/https://docs.raku.org/language/5to6-nutshell |archive-date=2024-12-03 |access-date=2024-12-06 |website=Raku documentation}}</ref> {{code|~~}} is called "the smartmatch operator" and its semantics depend on the type of the right-side argument. Namely, it checks numeric and string equalities, performs [[regular expression]] match tests (as opposed to {{code|{{=}}~}} in Perl<ref name="rakudocs-perl" />), and [[type checking]].<ref name="rakudocs-operators" />

<syntaxhighlight lang="raku">
my $concatResult = "Hello " ~ "world!";
$concatResult ~~ /<|w><[A..Z]><[a..z]>*<|w>/;

say $/; # outputs "Hello"
# the $/ variable holds the last regex match result
</syntaxhighlight>

In [[YAML]], the "Core schema," a set of aliases that processors are recommended to use, resolves a tilde as null.<ref>{{Cite web |date=2021-10-01 |title=YAML Ain't Markup Language (YAML™) revision 1.2.2 |url=https://yaml.org/spec/1.2.2/ |archive-url=https://web.archive.org/web/20241124004709/https://yaml.org/spec/1.2.2/ |archive-date=2024-11-24 |access-date=2024-11-28 |at=10.3.2. Tag Resolution}}</ref>

====Keyboards====
{{See also|QWERTY#Multilingual variants}}
The presence (or absence) of a tilde engraved on the keyboard depends on the territory where it was sold. In either case, computer's system settings determine the [[keyboard mapping]] and the default setting will match the engravings on the keys. Even so, it certainly possible to configure a keyboard for a different locale than that supplied by the retailer. On American and British keyboards, the tilde is a standard keytop and pressing it produces a free-standing "ASCII Tilde". To generate a letter with a tilde diacritic requires the [[US international]] or [[UK extended]] keyboard setting.
* With US-international, the {{key press|~}} key is a [[dead key]]: pressing that key and then a letter produces the tilde-accented form of that letter. (For example, {{key press|~}}{{nbsp}}{{key press|a}} produces {{char|ã}}.) With this setting active, an ASCII tilde can be inserted with the dead key followed by the space bar, or alternatively by striking the dead key twice in a row.
* With UK-extended, the key works normally but becomes a 'dead key' when combined with [[AltGr]]. Thus {{key press|AltGr|#}} followed by a letter produces the accented form of that letter.
* With a [[Mac (computer)|Mac]] either of the Alt/[[Option key|Option]] keys function similarly.
* With [[Linux]], the [[compose key]] facility is used.
Instructions for other national languages and keyboards are beyond the scope of this article.

==== Backup filenames ====
The dominant [[Unix]] convention for naming backup copies of files is appending a tilde to the original file name. It originated with the [[Emacs]] text editor<ref>{{cite web |title=GNU Emacs Lisp Reference Manual |url=https://www.gnu.org/software/emacs/manual/html_node/elisp/Backup-Names.html |publisher=Free Software Foundation, Inc. |access-date=2024-12-06 |at=27.1.4 Naming Backup Files - [https://www.gnu.org/software/emacs/manual/html_node/elisp/Backup-Names.html#index-make_002dbackup_002dfile_002dname Function: make-backup-file-name filename]}}</ref> and was adopted by many other editors and some command-line tools.

Emacs also introduced an elaborate numbered backup scheme, with files named {{mono|filename.~1~}}, {{mono|filename.~2~}} and so on.<ref>{{cite web |title=GNU Emacs Lisp Reference Manual |url=https://www.gnu.org/software/emacs/manual/html_node/elisp/Numbered-Backups.html |publisher=Free Software Foundation, Inc. |access-date=2024-12-06 |at=27.1.3 Making and Deleting Numbered Backup Files}}</ref> It didn't catch on, as the rise of [[version control]] software eliminates the need for this usage.{{Citation needed|date=December 2024}}

==== Microsoft filenames ====
The tilde was part of [[Microsoft]]'s [[filename mangling]] scheme when it extended the [[File Allocation Table|FAT]] file system standard to support long filenames for [[Microsoft Windows]]. Programs written prior to this development could only access filenames in the so-called [[8.3 filename|8.3 format]]—the filenames consisted of a maximum of eight characters from a restricted character set (e.g. no spaces), followed by a period, followed by three more characters. In order to permit these legacy programs to access files in the FAT file system, each file had to be given two names—one long, more descriptive one, and one that conformed to the 8.3 format. This was accomplished with a name-mangling scheme in which the first six characters of the filename are followed by a tilde and a digit. For example, "{{mono|Program Files}}" might become "{{mono|PROGRA~1}}".<ref>{{cite web |title=How Windows Generates 8.3 File Names from Long File Names |url=https://www.betaarchive.com/wiki/index.php?title=Microsoft_KB_Archive/142982 |publisher=Microsoft}}</ref>

The tilde symbol is also often used to prefix hidden temporary files that are created when a document is opened in Windows.{{Citation needed|date=October 2024|reason="Often" qualification should be cited}} For example, when a document "Document1.doc" is opened in Word, a file called "~$cument1.doc" is created in the same directory. This file contains information about which user has the file open, to prevent multiple users from attempting to change a document at the same time.<ref>{{Cite web |title=Description of how Word creates temporary files |url=https://support.microsoft.com/en-us/topic/description-of-how-word-creates-temporary-files-66b112fb-d2c0-8f40-a0be-70a367cc4c85 |archive-url=https://web.archive.org/web/20240919095253/https://support.microsoft.com/en-us/topic/description-of-how-word-creates-temporary-files-66b112fb-d2c0-8f40-a0be-70a367cc4c85 |archive-date=2024-09-19 |access-date=2024-10-03 |website=Microsoft Support}}</ref>
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===Juggling notation===
In the [[juggling notation]] system Beatmap, tilde can be added to either "hand" in a pair of fields to say "cross the arms with this hand on top". [[Mills' Mess]] is thus represented as (~2x,1)(1,2x)(2x,~1)*.<ref>{{cite web | url=http://www.jugglingdb.com/help/?id=125 | title=The Internet Juggling Database | archive-date=28 July 2005 | archive-url=https://web.archive.org/web/20050728104414/http://www.jugglingdb.com/help/?id=125 | access-date=6 November 2009}}</ref>