复制代码 代码如下:

<?php

/*

判断字符串是否存在的函数

*/

function strexists($haystack, $needle) {

return !(strpos($haystack, $needle) === FALSE);//注意这里的"==="

}

/*

Test

*/

$mystring = 'abc';

$findme = 'a';

$pos = strpos($mystring, $findme);

// Note our use of ===. Simply == would not work as expected

// because the position of 'a' was the 0th (first) character.

// 简单的使用 "==" 号是不会起作用的，需要使用 "==="，因为 a 第一次出现的位置为 0

if ($pos === false) {

echo "The string '$findme' was not found in the string '$mystring'";

} else {

echo "The string '$findme' was found in the string '$mystring'";

echo " and exists at position $pos";

}

// We can search for the character, ignoring anything before the offset

// 在搜索字符的时候可以使用参数 offset 来指定偏移量

$newstring= 'abcdef abcdef';

$pos= strpos($newstring, 'a', 1); // $pos = 7, not 0

?>