How to find a string inside other string

[atari]

Looking for a function in PHP or some way to find out if a string contains some other string.

[mod]

Let's say you have string $haystack = "mother" and string $needle = "other".

You want to find out if $haystack contains $needle.

One option is to use the strpos PHP function.

Code:

$pos = strpos($haystack,$needle);

if($pos === false) {
	// string needle NOT found in haystack
}
else {
	// string needle found in haystack
}

!! Watch out, this can be tricky. Some people do just something like if ($pos > 0) {} or perhaps something like if (strpos($haystack,$needle)) { } and forget that your string can be right at the beginning. if (strpos($haystack,$needle)) { } does not produce the same result as our code shown above.

Another option is to use strstr

Code:

if (strlen(strstr($haystack,$needle))>0) { echo "Needle Found"; }

Strstr function is case-sensitive. For a case-insensitive search, use stristr().
The strpos() function is faster and less memory intensive.

[bugibar]

I would include some checking for the string being empty too, maybe something like

Code:

<?php
function isempty($var) {
    if (((is_null($var) || rtrim($var) == "") && $var !== false) || (is_array($var) && empty($var))) {
        echo "yes<br />";
    } else {
        echo "no<br />";
    }
}
?>