php - Why is this strstr() returning false?

Question

I am trying to find whether a string contains a certain text or not using strstr()

$t = "http://site.com/image/d2737cda28cb420c972f7a0ce856cf22";
var_dump(strstr('/image/', $t));
exit;

But this gives false. Why is it giving fasle? How to fix it?

Answer 1

您的参数是倒置的（请参阅 参考资料strstr）。这是正确的使用方法：

strstr($t, '/image/');

Answer 2

您应该使用手册中的strpos，更快，更少的资源与您的 vars

<?php
$t = "http://site.com/image/d2737cda28cb420c972f7a0ce856cf22";
$findme   = '/image/';
$pos = strpos($t, $findme);

// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
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";
}
?>

Answer 3

试试这样

<?php
$t = "http://site.com/image/d2737cda28cb420c972f7a0ce856cf22";
var_dump(strstr($t, '/image/'));
exit;
?>

Answer 4

您可以查看该函数的文档。

验证语法。

php/文档/function.strstr.php

正确的用法是： var_dump(strstr($t, '/image/'));