Function with Default arguments in c++

Hello friends, in this post today, we learn about Function with Default arguments in c++. so lets start...

Function with default arguments 

Function with default arguments:-

In C ++ it is possible for a function not to specify all its arguments.

Some of the arguments may be specified their default values at the time of declaring the function.

 Default values are specified when the function is declared.

We must add default arguments from right to left.

We cannot provide a default value to a particular argument in the middle of an argument list.

Default arguments are useful in situations where some arguments always have the same value. For Example, passing marks.

In a function with default argument, if one argument is default, all successive arguments must be default. We cannot provide default values in the middle of the arguments or towards left side.

We provide few examples:

1. void fun(int x, int y = 20, int z=35); (valid)

2. void fun(int x, int y = 30, int z); (invalid)

3. void fun(int x = 45, int y); (invalid)

Out of three examples given only 1 is valid and 2 and 3 are invalid. In the 2 middle argument is default and the next argument z is not default. In the 3 first argument is default and next argument is not default.

Example:

//Function with default argument

#include<iostream>

using namespace std;

class default_arg

{

  public:

 void show(int=20,int=30, int=40);

};

void default_arg::show(int a,int b,int c)

{

cout<<"Argument to show was\n";

cout<<"a="<<a<<"\tb="<<b<<"\tc="<<c<<endl;

}

int main()

{

default_arg d;

d.show(1,2,3);

d.show(1,2);

d.show(1);

d.show();

return 0;

}

output:-

Argument to show was

a=1 b=2 c=3

Argument to show was

a=1 b=2 c=40

Argument to show was

a=1 b=30    c=40

Argument to show was

a=20    b=30    c=40

I hope that whatever information I have given in this post today, you have liked it and you have understood it.so keep learning and wait for the next post that will help you to increase your knowledge with the something new information.

Thank you so much for reading. And take care about yourself and your family.