関連ワード:  php check multidimensional array    php check multidimensional array for duplicate values    php search multidimensional array by value    php search multidimensional array by key    php search multidimensional array    php search multidimensional array for multiple values    php search multidimensional array for key and return value    php search multidimensional array by key value    php check if multidimensional array    php check if multidimensional array is empty