Java的算术运算符

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 result1 = num1 / num2;
		System.out.println(result1);//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
		System.out.println(result4);
		System.out.println(result5);
		System.out.println(result6);
		System.out.println(result7);
		
		
		// %：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);
		
		int m2 = -12;
		int n2 = 5;
		System.out.println("m2 % n2 = " + m2 % n2);
		
		int m3 = 12;
		int n3 = -5;
		System.out.println("m3 % n3 = " + m3 % n3);
		
		int m4 = -12;
		int n4 = -5;
		System.out.println("m4 % n4 = " + m4 % n4);
		
		
		//(前)++：先自增1，后运算
		//(后)++：先运算，后自增1
		int a1 = 10;
		int b1 = ++a1;
		System.out.println("a1 = " + a1 + ",b1 = " + b1);
		
		int a2 = 10;
		int b2 = a2++;
		System.out.println("a2 = " + a2 + ",b2 = " + b2);
		
		//(前)-- ：先自减1，后运算
		//(后)-- ：先运算，后自减1
		
		
	}
}

class AriExer {
	public static void main(String[] args) {
		int num = 140;
		
		int bai = num / 100;
		int shi = num % 100 / 10; //int shi = num / 10 % 10;
		int ge = num % 10;
		
		System.out.println("百位为：" + bai);
		System.out.println("十位为：" + shi);
		System.out.println("个位为：" + ge);
	}
}