Strange behaviour of strpos and Ø

Question

This seems odd to me but maybe there's a simple explanation.

Why does the following block of code result in false despite the needle definitely being part of the haystack?

if(strpos("Ø25xØ2", "Ø")){
    echo "true";
} else {
    echo "false";
}

Answer 1

strpos is finding that string at offset 0, which evaluates as false. To truly detect if it's not found, you need to explicitly check both type and value using either === or !== operators, for example:

if (strpos("Ø25xØ2", "Ø") !== false) {
    echo "true";
} else {
    echo "false";
}

This is quite well covered in the manual too.