PHP 5.4.33 Released

strcspn

(PHP 4, PHP 5)

strcspnFind length of initial segment not matching mask

Descrierea

int strcspn ( string $str1 , string $str2 [, int $start [, int $length ]] )

Returns the length of the initial segment of str1 which does not contain any of the characters in str2.

Parametri

str1

The first string.

str2

The second string.

start

The start position of the string to examine.

length

The length of the string to examine.

Valorile întoarse

Returns the length of the segment as an integer.

Exemple

Example #1 strcspn() example

<?php
$a 
strcspn('abcd',  'apple');
$b strcspn('abcd',  'banana');
$c strcspn('hello''l');
$d strcspn('hello''world');

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

Exemplul de mai sus va afișa:

int(0)
int(0)
int(2)
int(2)

Note

Notă: Această funcție acceptă și date binare.

Vedeți de asemenea

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

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User Contributed Notes 4 notes

up
0
AT-HE (at_he AT hotmai1 DOT com)
8 years ago
this function can be used like strspn(), except while that can be used to compare a string with an allowed pattern, this one can be use to compare a string with a FORBIDDEN pattern

so, to know if any forbidden character has a position inside our string, we can use (not tested with backslashes)...

<?php
// LARGE VERSION
$forbidden="\"\\?*:/@|<>";
if (
strlen($filename) != strcspn($filename,$forbidden)) {
    echo
"you cant create a file with that name!";
}

// SHORT VERSION
if (strlen($filename) - strcspn($filename,"\"\\?*:/@|<>")) {
    echo
"i told you, you cant create that file";
}
?>
up
0
maskedcoder at hotmail dot com
8 years ago
useful for finding beginning of quotes and/or tags in a variable containing html. 
    $pos = strcspn($data, '<"\'');
will find the first occurance of either the beginning of a tag, or a double- or single-quoted string.
up
-1
legacyprog at routinz dot net
3 years ago
When you use the third parameter remember that the function will return the number of characters it bypassed, which will *not* be the position in your source string.  It's a simple fix to just add your third parameter value to the function result to get the position in the first string where the scan stopped, but I didn't think of it at first.
up
-2
Anonymous
4 years ago
strcspn() can also be thought of as analogous to the following regular expression:
<?php
// where ... represents the mask of characters
preg_match('/[^ ...]/', substr($subject, $start, $length) );
?>
By this analogy, strcspn() can be used in place of some regular expressions to match a pattern without the overhead of a regex engine -- for example, ways to verify if an input string represents a binary value:
<?php
preg_match
('/^[01]+$/i', $subject);
// or...
!preg_match('/[^01]/i', $subject);

// ...or using strcspn()
!strcspn($subject, '01');
?>
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