Question

C++求解释谢谢

#include"iostream.h"
#include"math.h"
double sin(double x1,double x2)
{ return x1*x2;}
double sin(double x,int a)
{ return a+x;}
void main( )
{ double x;
cin>>x;//输入2
cout<<sin(x,x)<<endl;
cout<<sin(x,10)<<endl;
}
怎么算的

Answer 1

C++的函数重载.
sin(x,x) 两个参数都是double 所以调用
double sin(double x1,double x2)
{ return x1*x2;}
输出2*2=4
cout<<sin(x,10)<<endl; 第一个参数是double 第二个参数是int, 调用
double sin(double x,int a)
{ return a+x;}
输出10+2=12