C++ 运算符（算术、赋值、比较、逻辑）

1，算术运算符

#include <iostream>
using namespace std;

int main()
{
	//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，结果依然为整数，将小数部分去除,若要输入小数部分，可换doule数据类型

	//int a3 = 10;
	//int b3 = 0;
	//cout << a1 / b1 << endl;//错误！除数不能为0

	//两个小数相除
	double d1 = 0.5;
	double d2 = 0.23;
	cout << d1 / d2 << endl;

	//取模运算 本质：求余数 %%%%%%%%%%%%%%%%%%%%%%
	cout << a1 % b1 << endl;
	//cout << a3 % b3 << endl; //错误！除数不能为0
	//C++中规定，两个小数是不能做取模运算的，只有整型变量可以做取模运算

	//递增递减运算符 %%%%%%%%%%%%%%%%%%%%%%%%%%%%
	//1.前置递增
	int a = 10;
	++a;
	cout << a << endl;

	//2.后置递增
	int b = 10;
	b++;
	cout << b << endl;

	//3.前置和后置的区别
	//前置递增 先让变量+1 然后进行表达式运算
	int a2 = 10;
	int b2 = ++a2 * 10;
	cout << "a2=" << a2 << endl;//11
	cout << "b2=" << b2 << endl;//110

	//后置递增 先进行表达式运算 后让变量+1
	int a3 = 10;
	int b3 = a3++ * 10; //进行表达式运算，将100赋值给b3,a3再+1
	cout << "a3=" << a3 << endl;//11
	cout << "b3=" << b3 << endl;//100

	//前置递减 先让变量-1 然后进行表达式运算
	int a4 = 10;
	int b4 = --a4 * 10;
	cout << "a4=" << a4 << endl;//9
	cout << "b4=" << b4 << endl;//90

	//后置递减 先进行表达式运算 后让变量-1
	int a5 = 10;
	int b5 = a5-- * 10;
	cout << "a5=" << a5 << endl;//9
	cout << "b5=" << b5 << endl;//100

	system("pause"); //固定语句
	return 0;//固定语句
}

赋值运算符

#include <iostream>
using namespace std;

int main()
{
	//赋值运算符
	// =
	int a = 10;
	a = 100;
	cout << "a=" << a << endl;

	// +=
	a = 10;
	a += 2;//a = a+2
	cout << "a=" << a << endl; //12

	//-=
	a = 10;
	a -= 2;//a = a-2
	cout << "a=" << a << endl;//8

	// *=
	a = 10;
	a *= 2;//a = a*2
	cout << "a=" << a << endl;//20

	// /=
	a = 10;
	a /= 2;//a = a/2
	cout << "a=" << a << endl;//5

	// %=
	a = 10;
	a %= 2;//a = a%2
	cout << "a=" << a << endl;//0

	system("pause"); //固定语句
	return 0;//固定语句
}

比较运算符
用于表达式的比较，并返回一个真值或假值

#include <iostream>
using namespace std;

int main()
{
	//比较运算符
	// ==
	int a = 10;
	int b = 20;
	cout << (a == b) << endl; //0

	// !=
	cout << (a!= b) << endl;//1

	// >
	cout << (a > b) << endl;//0

	// <
	cout << (a < b) << endl;//1

	// >=
	cout << (a >= b) << endl;//0

	// <=
	cout << (a <= b) << endl;//1


	system("pause"); //固定语句
	return 0;//固定语句
}

逻辑运算符
用于根据表达式的值返回真值或者假值

#include <iostream>
using namespace std;

int main()
{
	//逻辑运算符  非 !  真变假 假变真
	//在C++中，除了0都为真  
	int a = 10;
	cout << !a << endl; //0
	cout << !!a << endl;//1 

	//逻辑运算符 与 && 同真为真，其余为假
	int b = 10;
	cout << (a && b) << endl;//1
	int c = 0;
	cout << (a && c) << endl;//0

	//逻辑运算符 或 || 同假为假，其余为真
	cout << (a || b) << endl;//1
	cout << (a || c) << endl;//1

	system("pause"); //固定语句
	return 0;//固定语句
}

本笔记为学习笔记

学习资源：https://www.bilibili.com/video/BV1et411b73Z?p=24

备注：
VS2015中光标变成方块状，输入时会把光标覆盖的部分替换掉的解决方法：
在键盘中找到insert键，按一下即可，有时候insert键简写为ins。