Editing AWK (section)

=== User-defined functions ===

In a format similar to [[C (programming language)|C]], function definitions consist of the keyword <code>function</code>, the function name, argument names and the function body.  Here is an example of a function.
<syntaxhighlight lang="awk">
function add_three(number) {
    return number + 3
}
</syntaxhighlight>

This statement can be invoked as follows:
<syntaxhighlight lang="awk">
(pattern) {
   print add_three(36)     # Outputs '''39'''
}
</syntaxhighlight>

Functions can have variables that are in the local scope. The names of these are added to the end of the argument list, though values for these should be omitted when calling the function. It is convention to add some [[whitespace character|whitespace]] in the argument list before the local variables, to indicate where the parameters end and the local variables begin.