PHP5中文手册·Find length of initial segment matching mask -- 追寻梦想＞编程乐园＞PHP 编程

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

Finds the length of the initial segment matching mask.

The line of code:


<?php
$var = strspn("42 is the answer, what is the question ...", "1234567890");
?>

will assign 2 to $var, because the string "42" will be the longest segment containing characters from "1234567890".

str1: The first string.
str2: The second string.
start: The start position of the string to examine. Negative value counts position from the end of a string.
length: The length of the string to examine. Negative value sets length from the end of a string.

Returns the length of the initial segment of str1 which consists entirely of characters in str2 .

版本	说明
4.3.0	The `start` and `length` parameters were added

Example#1 strspn() example


<?php
echo strspn("foo", "o", 1, 2); // 2
?>

Note: 本函数可安全用于二进制对象。