算术运算符

//测试算术运算符： + - + - * / % ++ -- +
class TestAri{
    public static void main(String[] args){
        
        // 除：/
        int i = 12;
        int j = i/5;
        double d = i / 5;
        double d1 = i/5.0;
        System.out.println(j);//2
        System.out.println(d);//2.0
        System.out.println(d1);//2.4
        //取模：%：取余数. 结果的符号取决于被模数
        int i1 = 12 % 5;
        int i2 = -12 % 5;
        int i3 = 12 % (-5);
        int i4 = -12 % (-5);
        System.out.println(i1);
        System.out.println(i2);
        System.out.println(i3);
        System.out.println(i4);
        //前++:先自增1，后做运算
        //后++:先做运算，后自增1

        int myInt1 = 10;
        int myInt2 = myInt1++;//后++
        System.out.println(myInt1);//11
        System.out.println(myInt2);//10

        int myInt3 = 10;
        int myInt4 = ++myInt3;//前++
        System.out.println(myInt3);//11
        System.out.println(myInt4);//11

        //前--:先自减1，后做运算
        //后--:先做运算，后自减1

    }
}

输入结果：

2
2.0
2.4
2
-2
2
-2
11
10
11
11