ArrayList实例化，arraylist实例

ArrayList实例化，arraylist实例

如何创建ArrayList？

ArrayList的实例化方法：ArrayList<String>List = new ArrayList<String>();

ArrayList:长度可变的数组，集合对象。动态的增加和减少元素；实现了ICollection和IList接口；灵活的设置数组                   的大小。

学生类：

package com.lenovo.listdemo;

public class Student {
     private String name;
     private String className;
     private int age;
     public Student() {}
     
	public Student(String name, String className, int age) {
		super();
		this.name = name;
		this.className = className;
		this.age = age;
	}

	public String getName() {
		return name;
	}

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

	public String getClassName() {
		return className;
	}

	public void setClassName(String className) {
		this.className = className;
	}

	public int getAge() {
		return age;
	}

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

测试类:

package com.lenovo.listdemo;

import java.util.ArrayList;

public class Test {
	public static void main(String[] args) {
		ArrayList<Student> studentList = new ArrayList<>();
		
		Student s1 = new Student();
		s1.setName("小明");
		s1.setClassName("一年级一班");
		s1.setAge(8);
		
		Student s2 = new Student("小红","二年级一班",9);
		Student s3 = new Student("小天","二年级二班",9);
		Student s4 = new Student("小白","二年级三班",9);
		Student s5 = new Student("小黑","二年级四班",9);
		Student s6 = new Student("小刚","二年级五班",9);

		
		studentList.add(s1);
		studentList.add(s2);
		studentList.add(s3);
		studentList.add(s4);
		studentList.add(s5);
		studentList.add(s6);
		
		studentList.remove(studentList.size()-1);//删除最后一行数据
		System.out.println();
		
		
		for(Student stu : studentList) {
			System.out.println("姓名："+stu.getName()+",年级："+stu.getClassName()+"，年龄："+stu.getAge());
		}
	}

复制行快捷键:Ctrl+Alt+↓；

删除一整行行快捷键：Ctrl+D。