Java13-Iterator的应用

一、Iterator常用的方法

• hasNext()检查集合中是否还有元素，返回布尔值
• 使用next()获得集合中的下一个元素

  二、迭代器的应用

package doudou;

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

public class test_Iterator {

    public static void main(String[] args) {
        System.out.println("================for循环======================");
        int[] a = { 1, 2, 3, 4, 2, 1 };
        for (int i = 0; i < a.length; i++) {
             System.out.println(a[i]);

        }
        System.out.println("=================iterator迭代-遍历====================");
        List<String> arr = new ArrayList<String>();
        arr.add("a");
        arr.add("b");
        arr.add("c");
        arr.add("d");
        arr.add("e");
        arr.add("f");
        Iterator<String> iter = arr.iterator();
        // iterator.hasNext()如果存在元素的话返回true
        while (iter.hasNext()) {
            // iterator.next()返回迭代的下一个元素
            System.out.print(iter.next() + "、");
//            if (iter.next() == "f") {
//                System.exit(0);
//            }
       
             if(iter.next().equals("f")){
             System.out.println("you get it");
             }
        }
        
        System.out.println("=================iterator迭代-遍历=====================");
        Collection c=new ArrayList<Students>();
        c.add(new Students("张三", "23", "女"));
        c.add(new Students("李四", "3", "女"));
        c.add(new Students("张私", "2", "男"));
        c.add(new Students("流三", "13", "女"));
        System.out.println(c);
        @SuppressWarnings("rawtypes")
        Iterator<Students>  it =c.iterator();
        while(it.hasNext()) {
            Students stu =it.next();
            System.out.println(stu.getName()+" "+stu.getAge()+" "+stu.getSex());
        }
    }
}

Students类

package doudou;

public class Students {
    private String name;
    private String age;
    private String sex;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public Students(String name, String age, String sex) {
        super();
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    
    

}