Special Characters to Use in PHP Expression Test Patterns

Regular PHP expressions use patterns to test whether the input users submit when using online forms are in the correct format. This table shows characters you can use in patterns.

Character	Meaning	Example	Match	Not a Match
^	Beginning of line	^c	cat	my cat
$	End of line	c$	tic	stick
.	Any single character	..	me, go	a
?	Preceding item is optional	mea?n	mean, men	moan
( )	Groups literal characters	m(ea)n	mean	men,mn
[ ]	Any character in set	abc[1-3]	abc1,abc2	abc4
[! ]	Any character not in set	m[!ea]n	min, mon	men, man
+	One or more	door[1-3]+	door111, door131	door, door55
*	Zero or more	door[1-3]*	door, door311	door4, door445
{ , }	Range of repetitions	a{2,5}	aa,aaaaa	a, xx3
\	Escapes character	m\*n	m*n	men, mean
( | | )	Alternate strings	(Tom|Tommy)	Tom, Tommy	Thomas, To

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