Let A=(1,2,3,4) and B=(a,b,c,d) .Give a function from A to B for each of the

Let A=(1,2,3,4) and B=(a,b,c,d) .Give a function from A to B for each of the following :
1) neither one-to-one nor onto.2)not one -to-one but onto .3) one-to-one but not onto .4) one -to- one but not onto .