This type of error generally occurs when the index is not set in the array. You can use the function isset in if like if( isset ( $array[‘focus’] ) && !empty( $array[‘focus’] ) ){ }. This code will first check either the index focus exists in the $array or not. If the index exists then it will check either it is empty or not. If it fulfills both conditions then it will enter in the body of the if and you will not see the undefined index error.
