C++教程:C++函数重载详解

float abs(float a)
{
   cout <<"float abs" <<endl;
   return (a>=0?a:-a);
}
double abs(double a)
{
   cout <<"double abs" <<endl;
   return (a>=0?a:-a);
}
运行结果：
int abs
int abs
a=5
b=3
float abs
float abs
c=2.4
d=8.4
double abs
double abs