[Super invincible and detailed Han Shunping's java notes] From beginner to proficient---keyboard input

Keyboard input statement

1 Introduction

In programming, if you need to receive user input data, you can use the keyboard to enter statements to obtain it. Input.java requires a scanner ( object ), which is Scanner

2 steps:

1) Import the package where this class is located , java.util.*

2) Create objects of this class (declare variables)

3) Call the functions inside

3 case demonstration:

Requirements: User information can be received from the console, [name, age, salary]

import java.util.Scanner;//表示把 java.util 下的 Scanner 类导入
    public class Input {
    //编写一个 main 方法
    public static void main(String[] args) {
    //演示接受用户的输入
    //步骤
    //Scanner 类 表示 简单文本扫描器，在 java.util 包
    //1. 引入/导入 Scanner 类所在的包
    //2. 创建 Scanner 对象 , new 创建一个对象,体会
    // myScanner 就是 Scanner 类的对象
        Scanner myScanner = new Scanner(System.in);
        //3. 接收用户输入了， 使用 相关的方法
        System.out.println("请输入名字");
        //当程序执行到 next 方法时，会等待用户输入~~~ String name = myScanner.next(); //接收用户输入字符串
        System.out.println("请输入年龄");
        int age = myScanner.nextInt(); //接收用户输入 int
        System.out.println("请输入薪水");
        double sal = myScanner.nextDouble(); //接收用户输入 double
        System.out.println("人的信息如下:");
        System.out.println("名字=" + name+ " 年龄=" + age + " 薪水=" + sal);
    }
}