Replace only at the end of the string

Question

echo $string can give any text.

How do I remove word "blank", only if it is the last word of the $string?

So, if we have a sentence like "Steve Blank is here" - nothing should not removed, otherwise if the sentence is "his name is Granblank", then "Blank" word should be removed.

Answer 1

You can easily do it using a regex. The \b ensures it's only removed if it's a separate word.

$str = preg_replace('/\bblank$/', '', $str);

Answer 2

As a variation on Teez's answer:

/**
 * A slightly more readable, non-regex solution.
 */
function remove_if_trailing($haystack, $needle)
{
    // The length of the needle as a negative number is where it would appear in the haystack
    $needle_position = strlen($needle) * -1;  

    // If the last N letters match $needle
    if (substr($haystack, $needle_position) == $needle) {
         // Then remove the last N letters from the string
         $haystack = substr($haystack, 0, $needle_position);
    }

    return $haystack;
}

echo remove_if_trailing("Steve Blank is here", 'blank');   // OUTPUTS: Steve blank is here
echo remove_if_trailing("his name is Granblank", 'blank');  // OUTPUTS: his name is Gran