java进阶_ArrayList遍历

存储字符串并遍历

代码演示

package com.tian.test;

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

public class ArrayListTest01 {
	public static void main(String[] args) {
		ArrayList<String> array = new ArrayList<String>();
        //一般都是这么写List<String> list = new ArrayList<String>();
		array.add("张三");
		array.add("李四");
		array.add("王五");
	/*	比较low的方式
	 *  System.out.println(array.get(0));
		System.out.println(array.get(1));
		System.out.println(array.get(2)); */
		
		//1.遍历集合的通用格式
		for(int i=0;i<array.size();i++) {
			String  s=array.get(i);
			System.out.println(s);
		}
		
		//2.迭代器
		Iterator<String> it=array.iterator();
		while(it.hasNext()) {
			System.out.println(it.next());
		}
		
		//3.增强for循环
		for(String ele:array) {
			System.out.println(ele);
		}
		
		//4.JDK1.8开始之后 Lamda表达式(扩展)
		array.forEach(s->{
			System.out.println(s);
		});
		
	}
}

存储学生对象并遍历

package com.tian.test;

import java.util.ArrayList;

public class ArrayListTest2 {
	public static void main(String[] args) {
		ArrayList<Student> array = new ArrayList<Student>();
		Student s1 = new Student("张三", 20);
		Student s2 = new Student("李四", 19);
		Student s3 = new Student("王五", 18);
		array.add(s1);
		array.add(s2);
		array.add(s3);
		for (int i = 0; i < array.size(); i++) {
			Student s = array.get(i);
			System.out.println(s);
			/*
			 *  Student [name=张三, age=20]
				Student [name=李四, age=19]
				Student [name=王五, age=18]
			*/
		}
	}
}

class Student {
	private String name;
	private int age;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public Student() {
	}

	public Student(String name, int age) {
		this.name = name;
		this.age = age;
	}

	@Override
	public String toString() {
		return "Student [name=" + name + ", age=" + age + "]";
	}

}