strip_tags

strcoll

[edit] Last updated: Fri, 07 Jun 2013

strcspn

(PHP 4, PHP 5)

strcspn — Возвращает длину участка в начале строки, не соответствующего маске

Описание

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

Возвращает длину участка в начале строки str1, который не содержит ни одного символа из строки str2.

Список параметров

str1: Первая строка.
str2: Вторая строка.
start: Начальная позиция сравнения строки.
length: Длина сравнения строки.

Возвращаемые значения

Возвращает длину фрагмента в виде целого числа.

Список изменений

Версия	Описание
4.3.0	Добавлены параметры `start` и `length`

Примеры

Пример #1 Пример использования strcspn()


<?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);
?>

Результат выполнения данного примера:

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

Примечания

Замечание: Эта функция безопасна для обработки данных в двоичной форме.

Смотрите также

strspn() - Возвращает длину участка в начале строки, полностью соответствующего маске

strip_tags

strcoll

[edit] Last updated: Fri, 07 Jun 2013

add a note User Contributed Notes strcspn - [6 notes]

down

Dmitry Mazur ¶

4 years ago


The second parameter simply is the set of the "stop"-characters.

In other words, this function will return the index (starting from 0) of a first occurence of the stop-character.

down

PHP at NospamImmortalSoFar dot com ¶

6 years ago


Also useful for breaking down expressions - for example parsing SQL: values ('this', fn("that,)()", 4))



$sep = strcspn ($list, "'\"`");     //    Start of quoted string

$list = substr ($list, $sep);

$find = substr ($list, 0, 1);

while (($sep = strpos ($list, $find, $sep+1)) > 0 && substr ($list, $sep-1, 1) == '\\')

    {}

//  $sep now spans the entire string, regardless of embedded quotes



Once the strings have been removed, an expression can then be parsed for commas and brackets without worrying about them:



while ($out != '')

{

    $sep = strcspn ($list, "(),");      //  Next seperator

...

}

down

AT-HE (at_he AT hotmai1 DOT com) ¶

7 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";

}

?>

down

maskedcoder at hotmail dot com ¶

7 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.

down

-1

legacyprog at routinz dot net ¶

2 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.

down

-1

Anonymous ¶

3 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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