Editing TI-BASIC (section)

== Examples ==

=== Hello world ===
The following programs, when executed, will display the phrase "<code>[[Hello world program|HELLO, WORLD!]]</code>".

==== TI-83/84 (Z80 Series) ====
<pre>
:Disp "HELLO, WORLD!"
</pre>

==== TI-89 (68k Series) ====
(P.S. this code can be shortened down to just the Disp function, like in the TI-83/84, and the hellowld, prgm, and endprgm are auto-generated.)<pre>
:hellowld()
:Prgm
:ClrIO
:Disp "HELLO, WORLD!"
:Pause
:ClrIO
:DispHome
:EndPrgm
</pre>

==== TI-Nspire ====
<pre>
text "HELLO, WORLD!"
</pre>

==== TI-Nspire CX ====
<pre>
text "HELLO, WORLD!"
</pre>

=== Lists and loops ===

==== TI-83/84 (Z80 Series) ====
<pre>
PROGRAM:LISTS
:"ASK FOR THE NUMBER OF VARIABLES
:Input "NUMBER OF VARS? ",A
:"VALIDATE INPUT OR STOP
:If A<1 or fPart(A)
:Stop
:"A FOR LOOP TO ASK FOR EACH VALUE TO BE IN THE LIST
:For(N,1,A)
:Input "VAR ",B
:"STORE THE VALUE INTO THE NTH ELEMENT
:B→L1(N)
:End
:"IMPLICITLY RETURN THE FINAL LIST
:L1
</pre>

==== TI-89 (68k Series) ====
<pre>
lists()
:Prgm
:  Local n,i,c © Declare local variables n, i, and c.
:  {}→list © Initialize list as an empty list.
:  Input "Number of variables?",n 
:  For i,1,n
:    Input "Variable #"&string(i),c © & concatenates i after it is converted to a string.
:    c→list[i]
:  EndFor
:EndPrgm
</pre>

Lists have many possible names, this allows for many programs to manipulate many lists without overriding previous data. Lists on the TI-82 cannot have custom names (L<sub>1</sub> through L<sub>6</sub> are preprogrammed). The TI-85 and TI-86 do not have the ability to handle a variable name with subscripts. The TI-81 is completely unable to handle lists. Lists can be used by the numerous built-in TI-BASIC functions for calculating statistics, including various [[Regression analysis|regression analyses]] and [https://education.ti.com/en/guidebook/details/en/123AB1F6CF524A188FCDDF107041A019/83 more].<ref name=":0" /> These can be called inside of programs, however they still show the info while pausing execution and they cannot store specific results into variables.

=== Recursion ===
Recursion is possible. A program can be called from within itself or from within another program.

==== TI-83/84 (Z80 Series) ====
The example below is used to compute [[factorial]]s. In order for it to work, <code>X</code> is the parameter of the factorial function and <code>A</code> must equal 1.

<pre>
PROGRAM:FACT
:If X=0
:Then
:Disp A
:Stop
:End
:XA→A
:X-1→X
:prgmFACT
</pre>

==== TI-89 (68k Series) ====

<pre>
factui()
:Prgm
:  Local n
:  Define fact(x)=Func
:    If x=0
:      Return 1
:    Return x*fact(x-1)
:  EndFunc
:  Input "Input a number", n
:  Disp "n! = "
:  Disp fact(n)
:EndPrgm
</pre>

=== Functions ===
The 68k series makes a distinction between programs and functions. Functions are just like programs except that they do not allow statements that perform I/O, including modifying non-local variables, and they return a value, which in the absence of an explicit <code>Return</code> statement is the last expression evaluated.

<pre>
fact(x)
:Func
:  If x=0
:    Return 1
:  If x<0
:    Return undef
:  x*fact(x-1)
:End Func
</pre>