PHP 问题 : strpos function not working

Question

为什么下面的 php 代码不起作用:

$string = "123";
$search = "123";

if(strpos($string,$search))
{
    echo "found";
}else{
    echo "not found";
}

因为 $search 在 $string 中 - 它不应该在找到时触发吗？

Answer 1

Manual: strpos() 中提到了这一点

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

在你的例子中，字符串在索引 0 和 php 0 == false 中找到

解决方案是只使用严格比较器

echo strpos($string,$search) === false
     ? "not found"
     : "found";

另一个

echo is_int(strpos($string,$search))
     ? "found"
     : "not found";

或者某事...让我们说有趣 :D 仅供说明。我不推荐这个。

echo strpos('_' . $string,$search) // we just shift the string 1 to the right
     ? "found"
     : "not found";