note 98123 modified in function.wordwrap by danbrown

If you need a function to cut only words longer than N characters, feel free to use the function below:

<?php
function wrap($str, $width=75, $break="\n") {
  return preg_replace('#(\S{'.$width.',})#e', "chunk_split('$1', ".$width.", '".$break."')", $str);
}

echo wrap('aaaa bbb cc dddd-dddd', 3, ' ');
?>

The above example will output: "aaa a  bbb  cc ddd d-d ddd "

--was--
If you need a function to cut only words longer than N characters, feel free to use the function below:

<?
function wrap($str, $width=75, $break="\n") {
  return preg_replace('#(\S{'.$width.',})#e', "chunk_split('$1', ".$width.", '".$break."')", $str);
}

echo wrap('aaaa bbb cc dddd-dddd', 3, ' ');
?>

The above example will output: "aaa a  bbb  cc ddd d-d ddd "

http://php.net/manual/en/function.wordwrap.php