如何在PHP中搜索多维数组中的值

I'm trying to see if for example the value "2001" exists in the following multidimensional array for the [terms] key and if it does, I will do nothing. If it doesn't exist, I need to add it into the array under [terms]:

Array
(
    [year] => Array
        (
            [singular] => Year
            [plural] => Years
            [filterable] => 1
            [use_on_listing] => 0
            [compare_value] => =
            [terms] => Array
                (
                    [0] => 2014
                    [1] => 2013
                    [2] => 2012
                    [3] => 2010
                    [4] => 2009
                    [5] => 2015
                    [6] => 1997
                )

        )
 )

Can't seem to figure it out using array_search though. Any help would be greatly appreciated.

Try this:

if(! in_array ( $year , $my_array['year']['terms']) ) //do stuff

Where $my_array is whatever the array name is, and $year is whatever year you choose.