In C++ we can pass class’s objects as arguments and also return them from a function the same way we pass and return other variables. No special keyword or header file is required to do so.
Passing an Object as argument
To pass an object as an argument we write the object name as the argument while calling the function the same way we do it for other variables.
Example: In this Example there is a class which has an integer variable ‘a’ and a function ‘add’ which takes an object as argument. The function is called by one object and takes another as an argument. Inside the function, the integer value of the argument object is added to that on which the ‘add’ function is called. In this method, we can pass objects as an argument and alter them.
Initial Values Value of object 1: 50 & object 2: 100 New values Value of object 1: 50 & object 2: 150
Returning Object as argument
object = return object_name;
Example: In the above example we can see that the add function does not return any value since its return-type is void. In the following program the add function returns an object of type ‘Example'(i.e., class name) whose value is stored in E3.
In this example, we can see both the things that are how we can pass the objects as well as return them. When the object E3 calls the add function it passes the other two objects namely E1 & E2 as arguments. Inside the function, another object is declared which calculates the sum of all the three variables and returns it to E3.
This code and the above code is almost the same, the only difference is that this time the add function returns an object whose value is stored in another object of the same class ‘Example’ E3. Here the value of E1 is displayed by object1, the value of E2 by object2 and value of E3 by object3.
Initial Values Value of object 1: 50, object 2: 100, object 3: 0 New values Value of object 1: 50, object 2: 100, object 3: 200
GeeksforGeeks has prepared a complete interview preparation course with premium videos, theory, practice problems, TA support and many more features. Please refer Placement 100 for details
- Passing by pointer Vs Passing by Reference in C++
- Declare a C/C++ function returning pointer to array of integer pointers
- Passing vector to a function in C++
- Passing a vector to constructor in C++
- Parameter Passing Techniques in C/C++
- How to delete an element from the Set by passing its value in C++
- Passing Reference to a Pointer in C++
- std::tuple, std::pair | Returning multiple values from a function using Tuple and Pair in C++
- Equation of straight line passing through a given point which bisects it into two equal line segments
- C++ Classes and Objects
- When are static objects destroyed?
- How to restrict dynamic allocation of objects in C++?
- Comparing String objects using Relational Operators in C++
- How to initialize Array of objects with parameterized constructors in C++
- Read/Write Class Objects from/to File in C++
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.