JavaSE学习（二）运算符、if语句

//逻辑与 &
int a = 10;
int b = 20;
int c = 30;
System.out.println(a < b & b < c);		//true & true = true
System.out.println(a < b & b > c);		//true & false = false
System.out.println(a > b & b < c);		//false & true = false
System.out.println(a > b & b > c);		//false & false = false

//逻辑与 |
System.out.println(a < b | b < c);		//true | true = true
System.out.println(a < b | b > c);		//true | false = true
System.out.println(a > b | b < c);		//false | true = true
System.out.println(a > b | b > c);		//false | false = false

//逻辑异或 ^ 两边相同为false，两边不同为true
System.out.println(a < b ^ b < c);		//true ^ true = false
System.out.println(a < b ^ b > c);		//true ^ false = true
System.out.println(a > b ^ b < c);		//false ^ true = true
System.out.println(a > b ^ b > c);		//false ^ false = false

int x = 3;
int y = 4;
//System.out.println((++x == 3) & (++y == 4));		//false & false = false
//System.out.println("x = " + x);					//x = 4
//System.out.println("y = " + y);					//y = 5

System.out.println((++x == 3 && (++y == 4));		//false && false = false
System.out.println("x = " + x);						//x = 4
System.out.println("y = " + y);						//y = 4

System.out.println(5 ^ 10 ^ 10);	//5
System.out.println(5 ^ 10 ^ 5);		//10

int x = 10;
int y = 5;
//不需要定义第三方变量，有弊端，有可能会超出int的取值范围
/*x = x + y;		//10 + 5 = 15
y = x - y;		//15 - 5 = 10
x = x - y;		//15 - 10 = 5*/

//不需要第三方变量，通过 ^ 来做
x = x ^ y;		//10 ^ 5
y = x ^ y;		//10 ^ 5 ^ 5 = 10
x = x ^ y;		//10 ^ 5 ^ 10 = 5

//左移，向左移动几位就是乘以2的几次幂
System.out.println(12 << 1);	//24
System.out.println(12 << 2);	//48

//右移，向右移动几位就是除以2的几次幂
System.out.println(12 >> 1);	//6
System.out.println(12 >> 2);	//3

System.out.println(2 << 3);//2 * 2 ^ 3，把2转为二进制，向左移动3位，直接操作二进制数

import java.util.Scanner;
class Demo2_Scanner {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);		//创建键盘录入对象
        int x = sc.nextInt();						//将键盘录入的数据存储在x中
        System.out.println(x);
    }
}