/* 运算符之一:算术运算符 + - + - * / % (前)++ (后)++ (前)-- (后)-- + */ class AriTest{ public static void main(String[] args){ //除号:/ int num1 = 12; int num2 = 5; int result = num1/num2; System.out.println(result);//2 int result2 = num1/num2*num2; System.out.println(result2);//10 double result3 = num1/num2; System.out.println(result3);//2.0 double result4 = num1/num2+0.0;//2.0 double result5 = num1/(num2+0.0);//2.4 double result6 = (double)num1/num2;//2.4 double result7 = (double)(num1/num2);//2.0 //%:取余运算 //结果的符号与被模数的符号相同 //开发中,经常使用%来判断能否被除尽的情况 int m1 = 12; int n1 = 5; System.out.println("m1 % n1="+m1 % n1);//2 int m2 = -12; int n2 = 5; System.out.println("m2 % n2="+m2 % n2);//-2 int m3 = 12; int n3 = -5; System.out.println("m3 % n3="+m3 % n3);//2 int m4 = -12; int n4 = -5; System.out.println("m4 % n4="+m4 % n4);//-2 //(前)++:先自增1,然后再运算 //(后)++ :先运算,后自增1 int a1 = 10; int b1 = ++a1; System.out.println("a1="+ a1 + ",b1="+b1);//11,11 int a2 = 10; int b2 = a2++; System.out.println("a2="+ a2 + ",b2="+b2);//11,10 int a3 = 10; a3++; int b3 = a3;//11 //注意点: short s1 = 10; //s1 = s1 + 1;//编译失败 s1 = (short)(s1 + 1);//正确 s1++;//自增1不会改变本身变量的数据类型 System.out.println(s1); //问题: byte bb1 = 127; bb1++; System.out.println("bb1=" + bb1);//-128 //(前)-- :先自减1,后运算 //(后)--:先运算,后自减1 int a4 = 10; int b4 = a4--;//int b4 = --a4; System.out.println("a4="+ a4 + ",b4="+b4);//9,10 } }