Question

I’m trying to find the position of all needles in a haystack:

$haystack = 'one twoo two one postpone twool';
$needles = array('one', 'two', 'three');
foreach ($needles as $needle) { 
  if (stristr($haystack, $needle)) { // list position of all needles
    $pos[strpos($haystack, $needle)] = $needle;
  }
}
print_r($pos);

The value of $pos is here:

Array ( [0] => one [4] => two ) 

However, expected was:

Array ( [0] => one [9] => two [13] => one) 

So two things go wrong:

• twoo is marked as being an occurence of two
• the loop apparently doesn’t match the second occurence of one

What am I doing wrong?

Answer 1

If you want an easy way, you could use preg_match:

foreach ($needles as $needle) {
    if( preg_match_all( '/\b' . $needle . '\b/', $haystack, $matches, PREG_OFFSET_CAPTURE ) ) {
        foreach( $matches[0] as $match )
            $pos[$match[1]] = $needle;
    }
}