Function for finding elements which are there in a [ ] but not in b [ ] .
< ? php function findMissing ( $ a , $ b , $ n , $ m ) { for ( $ i = 0 ; $ i < $ n ; $ i ++ ) { $ j ; for ( $ j = 0 ; $ j < $ m ; $ j ++ ) if ( $ a [ $ i ] == $ b [ $ j ] ) break ; if ( $ j == $ m ) echo $ a [ $ i ] , " ▁ " ; } }