手把手带你学习C++的运算符

来源：jb51　　时间：2021/11/23 14:29:41　　对本文有异议

运算符

作用：用于执行代码的运算

运算符类型	作用
算术运算符	用于处理四则运算
赋值运算符	用于将表达式的值赋给变量
比较运算符	用于表达式的比较，并返回一个真值或假值
逻辑运算符	用于根据表达式的值返回真值或假值

01 算术运算符

运算符	术语	示例	结果
+	正号	+3	3
-	负号	-3	-3
+	加	10+5	15
-	减	10-5	5
*	乘	10*5	50
/	除	10/5	2
%	取模/取余	10%3	1
++	前置递增	a=2;b=++a;	a=3;b=3;
++	后置递增	a=2;b=a++;	a=3;b=2;
--	前置递减	a=2;b=--a;	a=1;b=1;
--	后置递增	a=2;b=a--;	a=1;b=2;

#include<iostream>
using namespace std;
int main1()
{
	//加减乘除
	int a1 = 10;
	int b1 = 3;
	cout << a1 + b1 << endl;
	cout << a1 - b1 << endl;
	cout << a1 * b1 << endl;
	cout << a1 / b1 << endl; //两个整数相除，结果依然是整数，将小数部分去除
	int a2 = 10;
	int b2 = 20;
	cout << a2 / b2 << endl;
	int a3 = 10;
	int b3 = 0;
	//cout << a3 / b3 << endl; //错误，除数不可以为0
	double x1 = 0.5;
	double x2 = 0.22;
	cout << x1 / x2 << endl;
	//取模
	int c1 = 10;
	int d1 = 3;
	cout << c1 % d1 << endl;
	int c2 = 10;
	int d2 = 20;
	cout << c2 % d2 << endl;
	int c3 = 10;
	int d3 = 0;
	//cout << c3 % d3 << endl; //错误，取模除数不可以为0
	double x3 = 3.14;
	double x4 = 1.1;
	//cout << x3 % x4 << endl; //错误，不支持小数取模运算
	//1.前置递增
	int m = 10;
	++m;
	cout << "m = " << m << endl;
	//2.后置递增
	int n = 10;
	n++;
	cout << "n = " << n << endl;
	//3.前置和后置的区别
	//前置递增：先让变量+1，后进行表达式运算
	int m2 = 10;
	int n2 = ++m2 * 10;
	cout << "m2 = " << m2 << endl;
	cout << "n2 = " << n2 << endl;
	//后置递增：先进行表达式运算，后让变量+1
	int m3 = 10;
	int n3 = m3++ * 10;
	cout << "m3 = " << m3 << endl;
	cout << "n3 = " << n3 << endl;
	system("pause");
	return 0;
}

02 赋值运算符

运算符	术语	示例	结果
=	赋值	a=2;b=3;	a=2;b=3;
+=	加等于	a=0;a+=2;	a=2;
-=	减等于	a=5;a-=3;	a=2;
*=	乘等于	a=2;a*=2;	a=4;
/=	除等于	a=4;a/=2;	a=2;
%=	模等于	a=3;a%=2;	a=1;

#include<iostream>
using namespace std;
int main2()
{
	//赋值运算符
	int a = 10;
	cout << "a = " << a << endl; //10
	// +=
	a += 2;
	cout << "a = " << a << endl; //12
	// -=
	a = 10;
	a -= 2;
	cout << "a = " << a << endl; //8
	// *=
	a = 10;
	a *= 2;
	cout << "a = " << a << endl; //20
	// /=
	a = 10;
	a /= 2;
	cout << "a = " << a << endl; //5
	// %=
	a = 10;
	a %= 2;
	cout << "a = " << a << endl; //0
	system("pause");
	return 0;
}

03 比较运算符

运算符术语示例结果==相等于4==30!=不等于4!=31<小于4<30>大于4>31<=小于等于4<=30>=大于等于4>=31

#include<iostream>
using namespace std;
int main3()
{
	//比较运算符
	// ==
	int a = 10;
	int b = 20;
	cout << (a == b) << endl;
	// !=
	cout << (a != b) << endl;
	// >
	cout << (a > b) << endl;
	// <
	cout << (a < b) << endl;
	// >=
	cout << (a >= b) << endl;
	// <=
	cout << (a <= b) << endl;
	system("pause");
	return 0;
}

04 逻辑运算符

运算符术语示例结果!非!a如果a为假，则!a为真；如果a为真，则!a为假。&&与a&&b如果a和b都为真，则结果为真，否则为假。||或a||b如果a或b有一个为真，则结果为真；二者都为假时，结果为假。

#include<iostream>
using namespace std;
int main4()
{
	//逻辑运算符 非 !
	int a = 10;
	cout << !a << endl; //0
	cout << !!a << endl; //1
	//逻辑运算符 与 &&
	int c = 10;
	int d = 10;
	cout << (c && d) << endl; // 1
	c = 0;
	d = 10;
	cout << (c && d) << endl; // 0
	c = 10;
	d = 0;
	cout << (c && d) << endl; // 0
	c = 0;
	d = 0;
	cout << (c && d) << endl; // 0
	//逻辑运算符 或 ||
	int e = 10;
	int f = 10;
	cout << (e || f) << endl; // 1
	e = 0;
	f = 10;
	cout << (e || f) << endl; // 1
	e = 10;
	f = 0;
	cout << (e || f) << endl; // 1
	e = 0;
	f = 0;
	cout << (e || f) << endl; // 0
	system("pause");
	return 0;
}