If you want only part of the regex to be case insensitive (as my original answer presumed), then you have two options:
Read moreIs Preg_match case insensitive?
preg_match is case sensitive .
Read moreWhich of the following call to Preg_match will return false?
preg_match() returns 1 if the pattern matches given subject , 0 if it does not, or false on failure . This function may return Boolean false , but may also return a non-Boolean value which evaluates to false .
Read moreWhat is Preg_match?
The preg_match() function returns whether a match was found in a string .
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