C++ 数据类型
int\float\double的最值
#include <limits>
代码
cout << "INT_MIN is " << INT_MIN << endl;
cout << "INT_MAX is " << INT_MAX << endl;
cout << "LONG_MIN is " << LONG_MIN << endl;
cout << "LONG_MAX is " << LONG_MAX << endl;
cout << "FLT_MIN is " << FLT_MIN << endl;
cout << "FLT_MAX is " << FLT_MAX << endl;
cout << "DBL_MIN is " << DBL_MIN << endl;
cout << "DBL_MAX is " << DBL_MAX << endl;
结果
INT_MAX is 2147483647
LONG_MIN is -2147483648
LONG_MAX is 2147483647
FLT_MIN is 1.17549e-038
FLT_MAX is 3.40282e+038
DBL_MIN is 2.22507e-308
DBL_MAX is 1.79769e+308
float\double\int\long所占字节数
cout << "float = " << sizeof(float) << endl;
cout << "double = " << sizeof(double) << endl;
cout << "int = " << sizeof(int) << endl;
cout << "long = " << sizeof(long) << endl;
结果
float = 4
double = 8
int = 4
long = 4
c++的pow函数
代码
# include <iostream>
# include <cmath>
using namespace std;
int main()
{
cout <<pow(2,3)<<endl;
}
c++的time(0)函数
代码
#include <iostream>
using namespace std;
int main()
{
int allSeconds = time(0);
int currentSecond = allSeconds % 60;
int allMinutes = allSeconds / 60;
int currentMinute = allMinutes % 60;
int allHours = allMinutes / 60;
int currentHour = allHours % 24;
cout << currentSecond << endl;
cout << currentMinute << endl;
cout << currentHour << endl;
}
结果
当前秒:24
当前分:1
当前时:8