How to check if mcrypt extension exists in php

Question

I would like to know the simplest and fastest PHP code line to check if mcrypt extension is available/installed.

There is a function that encrypts a string and first it

Answer 1

You can also use extension_loaded():

if (extension_loaded('mcrypt')) {
    echo "mcrypt is loaded!";
} else {
    echo "mcrypt isn't loaded!";
}