I am trying to verify in PHP with preg_match that an input string contains only "a-z, A-Z, -, _ ,0-9" characters. If it contains just these, then validate.
I tried to search on google but I could not find anything usefull.
Can anybody help?
Thank you !
In PHP, you can use the preg_match() function to test whether a regular expression matches a specific string. Note that this function stops after the first match, so this is best suited for testing a regular expression more than extracting data.
Return Values ¶ 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 .
Definition and Usage The preg_match() function returns whether a match was found in a string.
The preg_match() function returns true if pattern matches otherwise, it returns false.
Use the pattern '/^[A-Za-z0-9_-]*$/'
, if an empty string is also valid. Otherwise '/^[A-Za-z0-9_-]+$/'
So:
$yourString = "blahblah";
if (preg_match('/^[A-Za-z0-9_-]*$/', $yourString)) {
#your string is good
}
Also, note that you want to put a '-' last in the character class as part of the character class, that way it is read as a literal '-' and not the dash between two characters such as the hyphen between A-Z.
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