集合遍历

package jike;

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

public class Main {
	public static void main(String[] args) {
		Collection list = new ArrayList();
		list.add(1);
		list.add("A");
		list.add(2);
		//1.使用数组遍历方法
		Object[] a = list.toArray();
		for (int i = 0; i < a.length; i++) {
			System.out.print(a[i]+" ");
		}
		System.out.println();
		//2.使用增强for循环遍历方法
		for (Object i: list) {
			System.out.print(i+" ");
		}
		System.out.println();
		//3.使用增强for循环遍历数组
		String[] str = new String[]{"A","B","C"};
		for (String s :str) {
			System.out.print(s+" ");
		}
	}
}

<pre name="code" class="java">package school.base.fun1;

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

public class Test5 {
	public static void main(String[] args) {
		ArrayList list = new ArrayList();
		list.add(123);
		list.add(890);
		list.add("aa");
		/*1.增强for循环遍历*/
		for (Object o: list) {
			System.out.println(o);
		}
		System.out.println();
		/*2.集合遍历*/
		Iterator iterator = list.iterator();
		while(iterator.hasNext()) {
			System.out.println(iterator.next());
		}
		System.out.println();
		/*3.一般遍历*/
		for (int i = 0; i < list.size(); i++) {
			System.out.println(list.get(i));
		}
	}
}