Collection set of commonly used functions

demo06 Package; 

Import of java.util.ArrayList; 
Import java.util.Collection; 

/ * 
* Classes in java.util 
interfaces Collection <E> 
* 
* top level interface for all single set, which defines a common set of methods for all single 
* arbitrary the method can use a separate set of interface collection 
* common method 
* boolean add (E e) 
          Ensures that this collection contains the specified element (optional operation). 
          * 
          * 
          * 
Void Clear () 
          Removes all elements (optional operation) from this collection. 
* * / 
Public class demo06 { 
    public static void main (String [] args) { 
// create a collection object polymorphic 
        Collection <String> = new new Coll the ArrayList <> (); 
        System.out.println (Coll); / / print empty rewrite toString method 

        / *
        * Public boolean add (E e) the given object to the current collection; 
        * return value is a boolean value, generally returns true, so you can not received; 
        * * / 
        boolean B1 = coll.add ( "John Doe "); 
        System.out.println (" B1 "+ B1); b1true // 
        System.out.println (Coll); 

// public Boolean remove (E E); deleted exists returns to true 
        Boolean coll.remove B2 = ( "Joe Smith"); 
        System.out.println (Coll); 

    } 
}