title: selecting an array key based on partial string
body: <p>I have an array and in that array I have an array key that looks like, <code>show_me_160</code> this array key may change a little, so sometimes the page may load and the array key maybe <code>show_me_120</code>, I want to now is possible to just string match the array key up until the last <code>_</code> so that I can check what the value is after the last underscore?</p>