Default - Arguments in C++

Default - Arguments in C++

-> C++ allows us to call a function without specifying all its Arguments.

-> In such a case, the function assigns a default value to the parameter which does not have a matching Argument in the function call.

-> Default values are specified when the functions is declared.
     Here is an example:
    
   float  amount (float p, int t, float r=5.5);
   value = amount (5000,7);    // one Argument missing
   value = amount (5000,5,7.25);   // no missing Argument

-> we can not provide a default value to a particular Argument in the middle of an Argument list.

Ex:     int  mul (int i, int j=5, int k=10);    // legal
           int  mul (int i=5, int j);    // illegal
           int  mul (int i=0, int j);    // illegal
           int  mul (int i=2, int j=5, int k=10);    // legal

// C++ Program on default Arguments.

#include<iostream>
using namespace std;
void interest (int p, float t, float r)
{
     float SI;
     SI= (p*t*r)/100;
     cout<<SI;
}
int main()
{
     interest(1000,1,12);
     return 0;
}

OUTPUT:
120

*NOTE: // void interest(int p, float t, float r=24)
// interest(1000,1);    (Rate is taken as 24 by default)