strspn
strspn
(PHP 4, PHP 5, PHP 7)
strspn — Finds the length of the initial segment of a string consisting entirely of characters contained within a given mask.
Description
int strspn ( string $subject , string $mask [, int $start [, int $length ]] )
Finds the length of the initial segment of subject
that contains only characters from mask
.
If start
and length
are omitted, then all of subject
will be examined. If they are included, then the effect will be the same as calling strspn(substr($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"); ?>
subject
that consists only of characters contained within "1234567890". Parameters
-
subject
-
The string to examine.
-
mask
-
The list of allowable characters.
-
start
-
The position in
subject
to start searching.If
start
is given and is non-negative, then strspn() will begin examiningsubject
at thestart
'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 strspn() will begin examiningsubject
at thestart
'th position from the end ofsubject
. -
length
-
The length of the segment from
subject
to examine.If
length
is given and is non-negative, thensubject
will be examined forlength
characters after the starting position.If
length
is given and is negative, thensubject
will be examined from the starting position up tolength
characters from the end ofsubject
.
Return Values
Returns the length of the initial segment of subject
which consists entirely of characters in mask
.
Note:
When a
start
parameter is set, the returned length is counted starting from this position, not from the beginning ofsubject
.
Examples
Example #1 strspn() 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() - Find length of initial segment not matching mask
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://secure.php.net/manual/en/function.strspn.php