for-each loop

[java]代码库

package cn.Tim.org;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.junit.Test;

public class ForeachDemo1 {

	@Test
	public void ArrayTest() {
		int arr[] = {1,2,3};
		for(int i: arr) {
			System.out.println(i);
		}
	}
	
	@Test
	public void SetTest() {
		List list = new ArrayList();
		list.add(1);
		list.add(2);
		list.add(3);
		
		for(Object obj : list) {
			int i = (Integer) obj;
			System.out.println(i);
		}
	}
	
	@Test
	public void MapOldTest() {
		Map map = new HashMap();
		map.put(1, "one");
		map.put(2, "two");
		map.put(3, "three");
		
		//通过keySet迭代Map
		
		Set set = map.keySet();
		Iterator it = set.iterator();
		while(it.hasNext()) {
			Integer key = (Integer)it.next();
			String value = (String)map.get(key);
			System.out.println(key + ":" + value);
		}
		
		
		//通过entrySet迭代Map
		
		Set set1 = map.entrySet();
		Iterator it1 = set1.iterator();
		while(it1.hasNext()) {
			Map.Entry entry = (Map.Entry) it1.next();
			Integer key = (Integer)entry.getKey();
			String value = (String)entry.getValue();
			System.out.println(key + ":" + value);
		}
	}
	
	@Test
	public void MapNewTest() {
		Map map = new HashMap();
		map.put(1, "one");
		map.put(2, "two");
		map.put(3, "three");
		
		//通过keySet,for-each来迭代Map
		
		for(Object obj : map.keySet()) {
			Integer key = (Integer)obj;
			String value = (String)map.get(key);
			System.out.println(key + ":" + value);
		}
		
		//通过entrySet,for-each来迭代Map
		for(Object obj : map.entrySet()) {
			Map.Entry entry = (Map.Entry) obj;
			Integer key = (Integer)entry.getKey();
			String value = (String)entry.getValue();
			System.out.println(key + ":" + value);
		}
	}

}

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