関連ワード:  php multidimensional array key value    php multidimensional array add key value    php multidimensional array search by key value    php multidimensional array sort by key value    php multidimensional array find key by value    php sort multidimensional array by specific key value    php multidimensional array get value by key    php multidimensional array search find key by specific value    php remove duplicates from multidimensional array by key value    php multidimensional array set value as key