STRSPN(3)								 1								 STRSPN(3)

strspn - Finds the length of the initial segment of a string consisting entirely of characters contained within a given mask.

SYNOPSIS
int strspn (string $subject, string $mask, [int $start], [int $length]) DESCRIPTION
Finds the length of the initial segment of $subject that contains only characters from $mask. If $start and $length are omitted, then all of $subject will be examined. If they are included, then the effect will be the same as call- ing strspn(substr($subject, $start, $length), $mask) (see "substr" for more information). The line of code: <?php $var = strspn("42 is the answer to the 128th question.", "1234567890"); ?> 2 to $var, because the string "42" is the initial segment of $subject that consists only of characters contained within "1234567890". PARAMETERS
o $subject - The string to examine. o $mask - The list of allowable characters. o $start - The position in $subject to start searching. If $start is given and is non-negative, then strspn(3) will begin examining $sub- ject at the $start'th position. For instance, in the string ' abcdef', the character at position 0 is ' a', the character at posi- tion 2 is ' c', and so forth. If $start is given and is negative, then strspn(3) will begin examining $subject at the $start'th position from the end of $subject. o $length - The length of the segment from $subject to examine. If $length is given and is non-negative, then $subject will be examined for $length characters after the starting position. If $length is given and is negative, then $subject will be examined from the starting position up to $length characters from the end of $subject. RETURN VALUES
Returns the length of the initial segment of $subject which consists entirely of characters in $mask. EXAMPLES
Example #1 strspn(3) example <?php // subject does not start with any characters from mask var_dump(strspn("foo", "o")); // examine two characters from subject starting at offset 1 var_dump(strspn("foo", "o", 1, 2)); // examine one character from subject starting at offset 1 var_dump(strspn("foo", "o", 1, 1)); ?> The above example will output: int(0) int(2) int(1) NOTES
Note This function is binary-safe. SEE ALSO
strcspn(3). PHP Documentation Group STRSPN(3)