PHP Search and remove numeric array value

php

Solution

foreach ($array as $key => $val)
    if (is_numeric($key)) // only numbers, a point and an `e` like in 1.1e10
        unset($array[$key]);

This unsets all the entries where there are only numbers.

Problem

I have a php array with strings and I'd like to delete the keys that have a string containing only numbers. How can I do that?

Original source