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This article mainly introduces the regular expression matching function of PHP preg_match. It introduces the function of preg_match function, parameter meaning, return value and usage method in more detail. It also gives examples of whether the preg_match output matches and the matching value. Related implementation skills, friends in need can refer to
This article describes the example of PHP preg_match to implement the regular expression matching function. Share it with everyone for your reference, the details are as follows:
preg_match — Execute a regular expression match
preg_match ( $pattern , $subject , $matches )
Search for a match between subject and the regular expression given by pattern.
Parameters:
pattern : Pattern to search for, string type (regular expression).
subject : Input string.
matches : (optional) If the parameter matches is provided, it will be populated as search results. $matches[0] will contain the text matched by the full pattern, $matches[1] will contain the text matched by the first captured subgroup, and so on.
Return value:
preg_match() returns the number of matches for pattern. Its value will be 0 (no match) or 1 because preg_match() will stop searching after the first match. preg_match_all() differs from this in that it searches for the subject until it reaches the end. If an error occurs preg_match() returns FALSE.
Instance 1:
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$label = 'content/112'; $a = preg_match('#content/(\d+)#i', $label, $mc); var_dump($a); var_dump($mc);Output:
int(1) array(2) { [0]=> string(11) "content/112" [1]=> string(3) "112" }
Instance 2:
$label = 'content/112'; $a = preg_match('#(\w+)/(\d+)#i', $label, $mc); var_dump($a); var_dump($mc);Output:
int(1) array(3) { [0]=> string(11) "content/112" [1]=> string(7) "content" [2]=> string(3) "112" }
Instance 3:
$label = 'content/112'; $a = preg_match('#content1111111/(\d+)#i', $label, $mc); var_dump($a); var_dump($mc);Output:
int(0) array(0) { }
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