带C ++示例的copysign()函数
C++copysign()函数
copysign()函数是cmath标头的库函数，用于获取带有第二个参数的符号的第一个参数的值，它接受两个参数(x,y)并以y的符号返回x的大小。
copysign()函数语法：
copysign(x, y);
参数：x，y–是以y为符号获得x大小的数字。
返回值：float/double/longdouble-根据给定的类型，它返回带有符号y的数字(x)。
示例
Input:
float x = 2.5;
float y = -2;
Function call:
copysign(x, y);
Output:
-2.5C++代码演示copysign()函数示例
//示例
//copysign()功能
#include <iostream>
#include <cmath>
using namespace std;
//main()部分
int main(){
float x;
float y;
x = 2.5;
y = -2;
cout<<"copysign("<<x<<","<<y<<"): "<<copysign(x,y)<<endl;
x = 2.5;
y = 2;
cout<<"copysign("<<x<<","<<y<<"): "<<copysign(x,y)<<endl;
x = 2;
y = -2;
cout<<"copysign("<<x<<","<<y<<"): "<<copysign(x,y)<<endl;
x = 2;
y = 2;
cout<<"copysign("<<x<<","<<y<<"): "<<copysign(x,y)<<endl;
x = -2.5;
y = -2.5;
cout<<"copysign("<<x<<","<<y<<"): "<<copysign(x,y)<<endl;
return 0;
}输出结果
copysign(2.5,-2): -2.5 copysign(2.5,2): 2.5 copysign(2,-2): -2 copysign(2,2): 2 copysign(-2.5,-2.5): -2.5
参考：C++copysign()函数