intersection+union+and+difference+of+arraylists+in+java

for search purposes: union intersection subtraction of lists or sets in java

use the retain all, remove all, and addall methods

Example

ArrayList list1 = useful_tools.stringWithCommasToArrayList("2,5,8"); ArrayList list2 = useful_tools.stringWithCommasToArrayList("3,5,9");

//list1.retainAll(list2);// list1.removeAll(list2); list1.addAll(list2); System.out.println(list1);