The Java Developers Almanac 1.4

e351. Operating on Lists

    // Create the lists
    List list1 = new ArrayList();
    List list2 = new ArrayList();
    
    // Add elements to the lists ...
    
    // Copy all the elements from list2 to list1 (list1 += list2)
    // list1 becomes the union of list1 and list2
    list1.addAll(list2);
    
    // Remove all the elements in list1 from list2 (list1 -= list2)
    // list1 becomes the asymmetric difference of list1 and list2
    list1.removeAll(list2);
    
    // Get the intersection of list1 and list2
    // list1 becomes the intersection of list1 and list2
    list1.retainAll(list2);
    
    // Remove all elements from a list
    list1.clear();
    
    // Truncate the list
    int newSize = 2;
    list1.subList(newSize, list1.size()).clear();

Related Examples

e349. Creating a List
e350. Sorting a List

See also: Arrays    Bits    Collections    Dates    Hash Tables    Property Files    Sets    Sorted Collections    Time    Timers

© 2002 Addison-Wesley.