How can i extract the portion of a string giving the beginning and the end position?

Question

How can i extract the portion of a string giving the beginning and the end position?

I know there is a method called substr() but is not what im looking for (the third parameter is lenght of the portion..)

Answer 1

If you have the start and end positions, the length is just end - start:

$string = "The quick brown fox jumped over the lazy dog";
$start = 4;
$end = 15;
substr($string, $start, $end - $start); //=> "quick brown"

See this in action at http://www.ideone.com/LRfYT.

Answer 2

If you know the beginning and end locations, all you have to do is subtract to get the length of the part you want. Then go ahead and use substr().

Answer 3

Th following will do what you want.

function ssubstr($string, $start, $end) {
    if ($end < 0) $length = strlen($string) + $end;
    else $length = $end - $start;
    return substr($string, $start, $length);
}

This method is safe for negative values of $end.

Note that it doesn't do any error checking