strcspn

(PHP 4, PHP 5, PHP 7)

Find length of initial segment not matching mask

int strcspn ( string $subject, string $mask [, int $start [, int $length ]] )

Returns the length of the initial segment of subject which does not contain any of the characters in 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 calling strcspn(substr($subject, $start, $length), $mask) (see substr for more information).

Parameters:

subject

The string to examine.

mask

The string containing every disallowed character.

start

The position in subject to start searching.

If start is given and is non-negative, then strcspn() will begin examining subject at the start'th position. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth.

If start is given and is negative, then strcspn() will begin examining subject at the start'th position from the end of subject.

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.

Returns:

Returns the length of the initial segment of subject which consists entirely of characters not in mask.

Note:

When a start parameter is set, the returned length is counted starting from this position, not from the beginning of subject.

Notes:

This function is binary-safe.

Examples:

strcspn() example

<?php
$a = strcspn('abcd',  'apple');
$b = strcspn('abcd',  'banana');
$c = strcspn('hello', 'l');
$d = strcspn('hello', 'world');
$e = strcspn('abcdhelloabcd', 'abcd', -9);
$f = strcspn('abcdhelloabcd', 'abcd', -9, -5);

var_dump($a);
var_dump($b);
var_dump($c);
var_dump($d);
var_dump($e);
var_dump($f);
?>

The above example will output:

int(0)
int(0)
int(2)
int(2)
int(5)
int(4)