java集合Collection中的常用方法

1

    Collection c=new ArrayList();    c.add("a");    c.add("b");    c.add("c");    c.add("d");//      c.remove("b");                          //删除指定元素//      c.clear();                              //清空集合//      System.out.println(c.contains("b"));    //是否包含b//      System.out.println(c.isEmpty());        //是否为空        System.out.println(c.size());           //获取元素个数        System.out.println(c);

2

    Collection c=new ArrayList();    boolean b1=c.add("abc");    boolean b2=c.add(true);    boolean b3=c.add(100);    boolean b4=c.add(new Student("zhangsan",23));    System.out.println(b1);    System.out.println(b2);    System.out.println(b3);    System.out.println(b4);    System.out.println(c.toString());