Exercise (1) create a set C1 to store the elements "one", "two", "three"“

 The original title is ：
*  Create a collection c1, Store elements "one","two","three"
*  Create another collection c2, Store elements "four","five","six"
*  And then c2 All elements are stored c1 aggregate 
*  Then create the set c3, Store elements "one,five"
*  Then output the set c1 Whether to include a collection c3 All elements of 
*  And then c1 In the collection "two" Delete before exporting c1 aggregate 、

Source code

public static void main(String[] args) {
    // Create a collection c1, Store elements "one","two","three"
    Collection<String> c1 =new ArrayList<String>();
    c1.add("one");
    c1.add("two");
    c1.add("three");
    // Create another collection c2, Store elements "four","five","six"
    Collection<String> c2 =new ArrayList<String>();
    c2.add("four");
    c2.add("five");
    c2.add("six");
    // And then c2 All elements are stored c1 aggregate 
    System.out.println(c2.addAll(c1));
    // Then create the set c3, Store elements "one,five"
    Collection<String> c3 = new ArrayList<String>();
    c3.add("one,five");
    // Then output the set c1 Whether to include a collection c3 All elements of 
    System.out.println(c1.containsAll(c3));
    // And then c1 In the collection "two" Delete before exporting c1 aggregate 
    c1.remove("two");
    System.out.println(c1);

}