算数运算符、自增自减运算符、赋值运算符、关系运算符、三元运算符

怼烎@ 2023-10-04 19:08 14阅读 0赞

#### 1、算数运算符 ####

==什么是运算符、什么是表达式==

**运算符就是对常量或变量操作的符号；表达式的意思是用运算符把常量或变量连接起来符合java语法的式子**

举例说明：

int a = 10;
    
    int b = 20;
    
    int c = a + b;
    
    这里的 ‘=’ ‘+’ 都是运算符；
    a+b 是表达式

![f00671dffa9a4586a74d555ac55e8bc6.png][]

![2ec4686e430447e685ba69bded7d8769.png][]![f70aa1e98e63442daa7e20409583fea4.png][]![75504ff955df46e1a46b0d08094790a7.png][]![7f68e87d01a545068b23a39e627e1859.png][]

==特别注意单引号的+是算术运算符用于相加；而双引号的+是连接作用不是相加作用。如：==

int a = 10;
    int b = 20;
    int c = a+b;
    System.out.println(c);// 输出结果是30
    
    int a = 10;
    int b = "20";
    int c = a+b;
    System.out.println(c);// 输出结果是1020

**==案例：数值拆分==**

需求：键盘录入一个三位数，将其拆分为个位、十位、百位后，打印在控制台

分析：

①：使用Scanner键盘录入一个三位数
    ②：个位的计算：数值 % 10
    	123 除以 10（商12，余数为3）
    ③：十位的计算：数值 / 10 % 10
    	123 除以 10 （商12，余数为3，整数相除只能得到整数）
    	12 除以 10 （商1，余数为2）
    ④：百位的计算：数值 / 100
    	123 除以 100	（商1，余数为23）

实现代码：

import java.util.*;
    public class Day02_demo1{
        public static void main(String args[]){
            Scanner in = new Scanner(System.in);
            int result = in.nextInt();
            int ge = result%10;
            int shi = result/10%10;
            int bai = result/100%10;
            System.out.println("您输入的数字的个位数是："+ge);
            System.out.println("您输入的数字的十位数是："+shi);
            System.out.println("您输入的数字的百位数是："+bai);
        }
    }
    
    int a = 1;

![66004ae56ef24c948d39f6f196db0ccb.png][]

![15a9a2182c934eab98ab8eec279ecdc3.png][]

#### 2、赋值运算符 ####

![f98d1a45e2244e6895412a2c4986f900.png][]![a0c1a53a7d3940e088b3ddef8ab12fab.png][]![4d643cae591548c9b57671a7d3495160.png][]3.关系运算符![326818d3b8cd4bae852018ad85478cf7.png][]

4.赋值运算符![351cffd6325745a7813115e2b29c3a01.png][]

#### 5、三元运算符 ####

![e578594c558f4556aafa4a1678fb7f31.png][]![56c2d7080a7e48bbbd5d686ee76a7242.png][]![9dd159b83e6142639ea5498e77dcc660.png][]

public class Day02_demo02 {
        public static void main(String[] args) {
            int height1 = 150;
            int height2 = 210;
            int height3 = 185;
            int tempHeight = 0;
            tempHeight  = (height1>height2)?height1:height2;
            System.out.println("最高的和尚是:"+((tempHeight>height3)?tempHeight:height3));
        }
    }
    
    int c = 900;
    System.out.println("最后的结果是:"+c);

[f00671dffa9a4586a74d555ac55e8bc6.png]: https://img-blog.csdnimg.cn/f00671dffa9a4586a74d555ac55e8bc6.png
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[326818d3b8cd4bae852018ad85478cf7.png]: https://img-blog.csdnimg.cn/326818d3b8cd4bae852018ad85478cf7.png
[351cffd6325745a7813115e2b29c3a01.png]: https://img-blog.csdnimg.cn/351cffd6325745a7813115e2b29c3a01.png
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