<?php

function limit_words($string, $word_limit)
{
    $words = explode(" ",$string);
    return implode(" ",array_splice($words,0,$word_limit));
}


# Example Usage

$content = "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";

echo limit_words($content,20);


?>

If you wanted to do this effect quickly, you could just use the function substr(). However, the substr() function only limits the number of characters being displayed. The returned result would be an excerpt of text that may or may not have the ending word cut-off.

Limit Words in a String

PHP