Set output Interface-iterator iteration output-old enumeration output: enumeration

1. Iterator iteration output (95%)

Iterator is the primary interface for the collection output, the interface is defined as follows:

 Public Interface Iterator<e> {        publicboolean//public         E Next () ;   // }        

Implementation code:

1  PackageCn.demo;2 3 Importjava.util.ArrayList;4 ImportJava.util.Iterator;5 Importjava.util.List;6 7  Public classTest {8      Public Static voidMain (string[] args)throwsException {9list<string> all =NewArraylist<string>();TenAll.add ("Java"); OneAll.add ("JSP"); AAll.add ("Oracle"); -Iterator<string> iter =all.iterator (); -      while(Iter.hasnext ()) { theString str =Iter.next (); - System.out.println (str); -     } -     } +}

Results:

Java
Jsp
Oracle

2. Old enumeration output: enumeration (4.96%)

This interface is defined as follows:

 Public Interface Enumeration<e> {        publicboolean//  Determine if there is a next element                                       Public // get current element }     

The collection interface does not define a method for acquiring a enumeration interface object, and the instantiated object of this interface relies on the vector class.

There are methods for defining this class: public enumeration<e> elements ();

The code is as follows:

1  PackageCn.demo;2 3 Importjava.util.Enumeration;4 ImportJava.util.Vector;5 6  Public classTest {7      Public Static voidMain (string[] args)throwsException {8vector<string> all =NewVector<string>();9All.add ("Java");TenAll.add ("JSP"); OneAll.add ("Oracle"); AEnumeration<string> ENU =all.elements (); -          while(Enu.hasmoreelements ()) { - System.out.println (Enu.nextelement ()); the         } -     } -}

Results:

Java
Jsp
Oracle

Summary: 1, iterator belongs to set the most standard practice, two methods: Hashnext (), Next ();

2, enumeration belongs to the vector legacy method, two methods: hasMoreElements (), Nextelement ().

Set output Interface-iterator iteration output-old enumeration output: enumeration