搜索字符串时使用strpos失败

Question

I have the following code/string: $ids="#222#,#333#,#555#";

When I'm searching for a part using:

if(strpos($ids,"#222#"))

it won't find it. But when I'm searching without the hashes, it works using:

if(strpos($ids,"222"))

I've already tried using strval for the search parameter, but this won't work also.

Answer 1

strpos starts counting from 0, and returns false if nothing is found. You need to check if it's false with === like this...

if (strpos($ids, '#222#') === false) // not found

Or use !== if you want the opposite test...

if (strpos($ids, '#222#') !== false) // found

See the PHP Manual entry for more information

Answer 2

You are not explecitely testing for FALSE when using strpos. Use it like this:

if(strpos($string, '#222#') !== FALSE) {
    // found
} else {
    // not found
}

---

Explanation: You are using it like this:

if(strpos($string, '#222#')) {
    // found
}

What is the problem with this? Answer: strpos() will return the position in string where the substring was found. In you case 0 as its at the beginning of the string. But 0 will be treated as false by PHP unless you issue an explicit check with === or !== .

Answer 3

It is working as expected. strpos() returns 0 because the string you're searching for is at the beginning of the word. You need to do an equality search:

Update your if() statement as follows:

if(strpos($ids, '#222') !== false)
{
    // string was found!
}

Answer 4

Try with this :

$ids="#222#,#333#,#555#";
if(strpos($ids,"#222#") !== false)
{
    echo "found";
}

You should use !== because the position of '#222#' is the 0th (first) character.