Java用ArrayList演示添加字符串元素、获取集合元素个数、分别用foreach、iterator、传统for循环、while、do while 5种方法遍历

/*
用ArrayList演示添加字符串元素、获取集合元素个数、分别用foreach、iterator、传统for循环、while、do while 5种方法遍历
*/

package com.zuoye;

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

public class ArrayListTest {
public static void main(String[] args) {
ArrayList mm = new ArrayList();
mm.add(“Good”);
mm.add(“Better”);
mm.add(“Best”);
System.out.println(“元素个数: " + mm.size());
System.out.println(“foreach遍历元素: “);
for (String s : mm) {
System.out.println(s + “\n”);
}
System.out.println(”--------------------------------”);
System.out.println(“使用Iterator遍历元素; “);
Iterator iterator = mm.iterator();
while (iterator.hasNext()) {
Object o = iterator.next();
String s = (String) o;
System.out.println(s + “\n”);
}
System.out.println(”---------------------------------”);
System.out.println(“使用传统for循环遍历”);
int i ;
for (i = 0; i < mm.size(); i++) {
Object o = mm.get(i);
String s = (String) o;
System.out.println(s+”\n");
}
System.out.println("-----------------------------------");
System.out.println("While循环遍历元素: ");
int j = 0;
while (j < mm.size()) {
Object o = mm.get(j);
String s = (String) o;
System.out.println(s + “\n”);
j++;
}
System.out.println("用do-while来遍历元素: ");
int k = 0;
do {
Object o = mm.get(k);
String s = (String) o;
System.out.println(s+ “\n”);
k++;
} while (k < mm.size());
}
}

打印结果: