Perl Programming/Modifiers

In addition to the basic control structures, Perl allows the use of statement modifiers. The statement modifier is placed at the end of the statement that it modifies. Note that the do {…} until (…) and do {…} while (…) loop constructs are actually statement modifiers. The complete list of modifiers is:

statement	⇗ ⇘	if	⇘ ⇗	expression
		while
statement	⇗ ⇘	unless	⇘ ⇗	expression
		until
statement	⇒	foreach	⇒	list

Unlike BASIC-PLUS, statement modifiers in Perl cannot be stacked.