数组 --------集合 中的各种遍历方法!!!!!

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(包名用了中文,大家不要在意这个)

1.数组

    1.for

2.增强for

package 杨彬_数组;

public class ArrayDemo {
	/*
	 * 数组遍历的方式: 1.for 2.增强for
	 */
	public static void main(String[] args) {
		int[] arr = { 1, 2, 3, 4, 5 };
		test1();
		test2(arr);
	}
	//增强for
	private static void test2(int[] arr) {
		for(int i : arr){
			System.out.println(i);
		}
	}

	//for
	private static void test1() {
		int[] arr = { 1, 2, 3, 4, 5 };
		for (int i = 0; i< arr.length; i++) {
			System.out.println(arr[i]);
		}
	}
	
}

2.Collection

1.for

2.增强for

3.迭代器

4.toArray

package 杨彬_Collection;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

/*
 * 遍历方式  :  1. for(不写了)  2,增强for  3.迭代器 4.toArray
 */
public class CollectionDemo {
	public static void main(String[] args) {
		Collection<String> c = new ArrayList<String>() ;
		c.add("杨彬");
		c.add("郭乐乐");
		c.add("科比");
		c.add("乔丹");
//		test1(c);
//		test2(c);
		test3(c);
	}
	//toArray
	private static void test3(Collection<String> c) {
		Object[] cc = c.toArray();
		for(int i=0;i<cc.length;i++){
			System.out.println(cc[i]);
		}
	}
	//迭代器
	private static void test2(Collection<String> c) {
		Iterator<String>  it = c.iterator(); 
		while(it.hasNext()){
			System.out.println(it.next());
		}
	}
	//增强FOR
	private static void test1(Collection<String> c) {
		for(String c1 : c){
			System.out.println(c1);
		}
	}
}

3.List

package 数组_List;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

/*
 * for
 * 增强for
 * 迭代器
 * list特有迭代器
 * 角标get()
 * toArray()
 */
public class ListDemo {
	public static void main(String[] args) {
		List<String> c = new ArrayList<String>() ;
		c.add("杨彬");
		c.add("郭乐乐");
		c.add("科比");
		c.add("乔丹");
		
	
		
//		test1(c);
//		test2(c);
//		test3(c);
//		test4(c);
		test5(c); 
		test6(c);
	
}
	private static void test6(List<String> c) {
		for(ListIterator<String> lit = c.listIterator(); lit.hasNext();){
			System.out.println(lit.next());
		}
	}
	//toArray()
	private static void test5(List<String> c) {
		Object[] array = c.toArray();
		for(int i=0;i<array.length;i++){
			System.out.println(array[i]);
		}
	}
	//角标get();
	private static void test4(List<String> c) {
		for(int i=0;i<c.size();i++){
			System.out.println(c.get(i));
		}
	}
	//LIst迭代器
	private static void test3(List<String> c) {
		ListIterator<String> lsc = c.listIterator();
		while(lsc.hasNext()){
			System.out.println(lsc.next());
		}
	}
	//迭代器
	private static void test2(List<String> c) {
		Iterator<String> it = c.iterator();
		while(it.hasNext()){
			System.out.println(it.next());
		}
	}
//增强for
	private static void test1(List<String> c) {
		for(String c1: c){
			System.out.println(c1);
		}
	}

}

3.Set

package 杨彬_Set;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
/*
 * 迭代器
 * 增强for
 * toArray
 * 
 */
public class SetList {
	public static void main(String[] args) {
		Set<String> c = new HashSet<String>() ;
		c.add("杨彬");
		c.add("郭乐乐");
		c.add("科比");
		c.add("乔丹");
//		test2(c);
		//test1(c);
		test3(c);
	}
	//toArray()
	private static void test3(Set<String> c) {
		Object[] array = c.toArray();
		for(int i=0;i<array.length;i++){
			System.out.println(array[i]);
		}
	}
	//增强for
	private static void test2(Set<String> c) {
		for(String s:c){
			System.out.println(s);
		}
	}
//迭代器
	private static void test1(Set<String> c) {
		Iterator<String> it = c.iterator();
		while(it.hasNext()){
			System.out.println(it.next());
		}
	}
}

4.Map

package 杨彬_Map;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;
/* VAlues
 * keyset
 * entryset
 */
public class MapDemo {
	public static void main(String[] args) {
		Map<Integer, String> c = new HashMap<Integer, String>() ;
		c.put(1,"杨彬");
		c.put(2,"郭乐乐");
		c.put(3,"科比");
		c.put(4,"乔丹");
//		test1(c);
//		test2(c);
		test3(c);
	}
	private static void test3(Map<Integer, String> c) {
		for(Entry<Integer, String> entry : c.entrySet()){
			System.out.println(entry.getKey()+":"+entry.getValue());
		}
	}
	//keyset
	private static void test2(Map<Integer, String> c) {
		Set<Integer> set = c.keySet();
		for(Integer key : set){
			String value1 = c.get(key);
			System.out.println(key+":"+ value1);
		}
	}
//Values 只能取值 
	private static void test1(Map<Integer, String> c) {
		Collection<String> co = c.values();
		for(String s : co){
			System.out.println(s);
		}
	}

}

数组 --------集合 中的各种遍历方法!!!!!

标签：style   blog   io   ar   sp   for   java   strong   on   

原文地址：http://blog.csdn.net/yangbin0513/article/details/41761233