Inline Function in C++ with Example

Inline Function:

An inline function is a function that is expanded in line when it is invoked, the compiler replaces the function call with the corresponding function code.
It has the following syntax:

inline function-header
{
 functions of the body
}

Example :
inline float square (float a)
{
  return(a*a);
}

Example:

#include<iostream.h>
#include<conio.h>
using namespace std;
inline float add(float a, float b)
{
 return(a+b);
}
inline double sub(double c, double d)
{
 return(c-d);
}
int main()
{
 float x=15.7567;
 float y=12.56;
cout<<add(x,y)<<endl;
cout<<sub(x,y)<<endl;
return 0;
}

Default Arguments:

C++ allows us to call a function without specifying all its arguments. The function assigns a default values to the parameters which do not have a matching argument in the function call. Default Arguments in C++ are checked for data type at the time of declaration and evaluated at the time of the call. In this case, only Default Arguments in C++ can have default values and we must add defaults from right to left, we can’t provide a default value to a particular argument in the middle of an argument list.
Example:

#include<iostream.h>
#include<conio.h>
using namespace std;
int main()
{
 float amount;
 float value(float p, int n, float r=0.15);
void printline(char ch='*', int l=50);
printline();
amount=value(75000.500, 6);
cout<<"Final value="<<amount<<endl;
amount=value(12000.750, 7,0.50);
cout<<"Final value="<<amount<<endl;
printline('*');
getch();
return 0;
}
float value(float p, int n, float r)
{
 int y=1;
float sum=p;
while(y<=n)
{
 sum=sum*(1+r);
 y=y+1;
}
return(sum);
}
void printline(char ch, int l)
{
 for(int i=1;i<=l;i++)
 printf("%c",ch);
printf("\n");
}