Editing Icon (programming language) (section)

===Basic syntax===
The Icon language is derived from the [[ALGOL]]-class of [[structured programming]] languages, and thus has syntax similar to [[C (programming language)|C]] or [[Pascal (programming language)|Pascal]]. Icon is most similar to Pascal, using {{code |1=:=}} syntax for assignments, the {{code|procedure}} keyword and similar syntax. On the other hand, Icon uses C-style braces for structuring execution groups, and programs start by running a procedure called {{code|main}}.{{sfn|Griswold|Griswold|2002|p=xv}}

In many ways Icon also shares features with most [[scripting language]]s (as well as [[SNOBOL]] and SL5, from which they were taken): variables do not have to be declared, types are cast automatically, and numbers can be converted to strings and back automatically.{{sfn|Griswold|Griswold|2002|p=xvi}} Another feature common to many scripting languages, but not all, is the lack of a line-ending character; in Icon, lines that do not end with a semicolon get ended by an implied semicolon if it makes sense.{{sfn|Griswold|Griswold|2002|p=10}}

Procedures are the basic building blocks of Icon programs. Although they use Pascal naming, they work more like C functions and can return values; there is no {{code|function}} keyword in Icon.{{sfn|Griswold|Griswold|2002|p=1}}

<syntaxhighlight lang="icon">
 procedure doSomething(aString)
   write(aString)
 end
</syntaxhighlight>