整数计算

输出

package hello;

public class Hello {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
        System.out.println("Hello World");
	}

}

注意：寻找类的快捷键Alt + / 选中文本：Ctrl + /

赋值计算

package hello;

import java.util.Scanner;

public class Hello {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println("Hello World");
        Scanner in = new Scanner(System.in);
//        System.out.println("echo:" + in.nextLine());
//        System.out.println("2 + 3 = " + (2+3));
        int amount;
        int price;
        System.out.println("请输入票面:");
        amount = in.nextInt();
        System.out.println("请输入金额:");
        price = in.nextInt();
        System.out.println(amount + "-" + price + "=" + (amount-price));
	}

}

常量 final int