selecting an array key based on partial string

[retardo]

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?