As you know, when it comes to validating incoming data, PHP 5 comes bundled with a powerful set of native functions that allow you to perform all sorts of clever validations on a given variable. [...] In this second chapter of this series, I'm going to discuss how to use the FILTER_VALIDATE_INT filter that you learned in the previous part, this time for validating array elements as well as octal and hexadecimal integers.

Their example loops through an array of values to locate the ones that match the FILTER_VALIDATE_INT filter and echo their value back to the user via a foreach loop.