C++学习02之输入输出和运算符

#include
using namespace std;

//数据的输入
int main()
{
	//1.整型
	int a = 0;
	cout << "请给整型变量a赋值:" << endl;
	cin >> a;
	cout << "整型变量a=" << a << endl;
	//2.浮点型
	float b = 3.14f;
	cout << "请给浮点型变量b赋值:" << endl;
	cin >> b;
	cout << "浮点型变量b=" << b << endl;
	//3.字符型
	char c = 'c';
	cout << "请给字符型变量c赋值：" << endl;
	cin >> c;
	cout << "字符变量c=" << c << endl;
	//4.字符串类型
	string d = "我在学习安卓";
	cout << "请给字符串d赋值：" << endl;
	cin >> d;
	cout << "字符串d为：" << d << endl;
	//5.布尔类型 布尔类型只要是非0的值输出都是1，为true
	bool f = false;
	cout << "请给布尔类型变量f赋值：" << endl;
	cin >> f;
	cout << "布尔类型变量f为：" << f << endl;
	return 0;
}

#include
using namespace std;
int main() {

	//加减乘除
	int a1 = 10;
	int b1 = 3;
	cout << a1 + b1 << endl;//13
	cout << a1 - b1 << endl;//7
	cout << a1 * b1 << endl;//30

	//两个整数相除，会得到一个整数，去除小数部分
	cout << a1 / b1 << endl;//3

	int a2 = 10;
	int b2 = 20;
	cout << a2/b2 << endl;//0
	system("pause");
	return 0;
}

#include
using namespace std;
int main() {


	//取模运算实质就是求余数,两个小数是不可以做取模运算的

	int a1 = 10;
	int b1 = 3;
	cout << a1 % b1 << endl;

	//递增，递减运算符
	// 
	int b = 2;
	int c = 10;
	int d = 10;
	//1.前置递增,前置递增在运算中，先做自身的递增，再参与运算
	++b;
	cout << b << endl;//3
	int f = ++c * 10;
	cout << "f的值为：" << f << endl;//110
	cout << c << endl;//11
	//2.后置递增，后置递增在运算中，先参与运算，再做自身的递增
	b++;
	cout << b << endl;//4
	int e = d++ * 10;
	cout << "e的值为" << e << endl;//100
	cout << d << endl;//11
	system("pause");
	return 0;
}

#include
using namespace std;
int main() {

//赋值运算符

	int a = 10;
	//=
	a = 100;
	cout << "a=" << a << endl;//100
	//+=
	a = 10;
	a += 2;//相当于a=a+2;
	cout << "a+=2  =" << a << endl;//12
	//-=
	a = 10;
	a -= 2;//相当于a=a-2;
	cout << "a-=2  =" << a << endl;//8
	//*=
	a = 10;
	a *= 2;//相当于a=a*2;
	cout << "a*=2  =" << a << endl;//20
	// /=
	a  = 10;
	a /= 2;//相当于a=a/2;
	cout << "a/=2  =" << a << endl;//5
	//%=
	a = 10;
	a %= 2;//相当于a=a%2;
	cout << "a%=2  =" << a << endl;//0
	system("pause");
	return 0;
}

#include
using namespace std;
int main() {
	int a = 10;
	int b = 20;
	//比较运算符
	// ==
	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");
	return 0;
}

#include
using namespace std;
int main() {
	int a = 10;
	int b = 20;
	int c = 0;
	int d = 0;

	//逻辑运算符  在C++中非0即为真
	// ！非   ！假为真，！真为假
	cout << !a << endl;//0
	cout << !!a << endl;//1

	//&& 与 同真为真，其余为假
	cout << (a && b) << endl;//1
	cout << (a && c) << endl;//0

	//|| 或  同假为假，其余为真
	cout << (a || b) << endl;//1
	cout << (a ||c) << endl;//1
	cout << (c || d) << endl;//0
	cout << (c || b) << endl;//1
	system("pause");
	return 0;
}