Skip to main content

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 in c++, function with default arguments
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=30int=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.



Comments

Popular posts from this blog

Inheritance in c++

Hello friends, in this post today, we learn about Inheritance in c++ concept and types of inheritance in c++ . Which  is very important. so lets start... Inheritance  Inheritance   Class can acquire the properties and methods of another class. Inheritance is the process of deriving a new class from an already existing class. In other words" Inherit all the properties and methods of class into another class, is called Inheritance." Inheritance  provides the idea of reusability i.e., code once written can be used again and again in number  of new classes. The new class is called derived class and old class is called base class. The new class can use all or some of the features of the already existing  class and the programmer can define his own members to the new class. Types of Inheritance In c++, there are 5 types of inheritance. Types of Inheritance Syntax of Inheritance:- class derived_classname : access_spacifier base_classname Where class is keyword used to create a clas

Constructor in c++

Hello friends, in this post today, we learn about  what is constructor in c++ and types of constructor . so lets start... Constructor in c++ Constructor:-   A constructor is a “special” member function which initializes the objects of class.  Constructor is used to solve problem of initialization. Properties of constructor:- Constructors are used to construct the object of the class. Constructor name must be same as class name. Constructor is invoked automatically when objects of the class are created. The constructors are always declared in the public section. If declared in the private section then objects are can only be created inside the member functions but serve no purpose. It must be an instance member function , that is, it can never be static. Constructors  do not have any return type not even void so they cannot return any value. Constructor can also be overloaded. Constructors cannot be inherited, but they can be called from the constructors of derived  class . Constructor

What is scope resolution operator in c++

Hello friends, in this post today, we will learn about What is scope resolution operator in c++ and how to use in our program. so let's start.... Scope resolution operator  Scope resolution operator :- Scope resolution operator which is also known as ( membership lable ), represnted as (::) . The scope resolution operator is employed to resolve or extend the scope of variable or functions. C++ is block structured language. We know that the same variable or function name can be used to have different meaning in different block. The scope resolution operator will refer value of worldwide variable or function from anywhere (also from inner block). Without scope resolution operator all variable will refer local value. Example for variabe: #include   <iostream>   using   namespace   std ; int  m= 10 ; int   main () {       int  m= 20 ;      {       int  k=m;        int  m= 30 ;     cout<< "we are in inner block \n " ;      cout<< "k=" <<k<