Does PHP have a function that returns the correct file extension given a valid content type?

Does PHP have a function that returns a file extension given a content type?

I'm looking for something that works like:

<?php
function getFileExtension($contentType)
{
    if ($contentType === 'image/png')
    {
        return '.png';
    }
    elseif ($contentType === 'image/jpg')
    {
        return '.jpg';
    }
    elseif ($contentType === 'application/zip')
    {
        return '.zip';
    }
    else
    {
        return FALSE;
    }
}

The goal is to use a library function that has all content types handled. Based on the pattern above, I guess I could roll my own with something like this:

<?php
function getFileExtension($contentType)
{
    $pieces = explode('/', $contentType);
    return '.' . array_pop($pieces);
}

... but that seems janky. Anybody know of an already authored PHP solution? LMK. Thanks!