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C++ functions: first steps

4 min readNov 26, 2022

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Introduction

Code is a tool for solving a problem in an intelligent programming way. Functions fall within the framework of making the code readable, fragmented, and can be understood when returning to it.

C++ functions fall into this framework. This article is an introduction to C++ functions.

What are C++ functions?

C++ functions are important in the C++ language. They allow the programmer to separate different parts of a program into different sections, which can be reused and called by other parts of the program.

Functions are a way to break up large programs into smaller, more manageable parts. Functions can be used for many purposes: for example, one function might check if someone is old enough to vote, while another might calculate the total cost of an order.

C++ functions

Functions are an important part of C++ because they provide a way to organize your code logically and make it easier to maintain later on.

Why are C++ functions essential?

Functions are a set of predefined commands that can be used to accomplish tasks. They can be used as building blocks for more complex programs.

The function is a self-contained block of code that performs a specific task and returns the result, often with a value.

Functions are the building blocks for any program and are an essential aspect of programming languages such as C++.

Functions in C++ provide programmers with an easy way to reuse code and modularize their programs.

Declaring functions in C++

Declaring functions in C++ is a vital part of the development process. Functions are used to construct the program more manageable and to separate tasks into smaller, more manageable chunks.

When declaring a function in C++, many things need to be included:

  • The return type of the function.
  • The name of the function.
  • The parameters (if any) that should be passed into the function,
  • And finally, what type of data will be returned from the function?

Inside the C++ function, the programmer can read input, process input, and provide an output.

C++ function

VOID RETURN TYPE C++ FUNCTION

int main(){
statement 1
statement 2
statement 3
statement 4
statements 5
return 0;
}

Modularization in C++ Program

In C++ programming, modules are separate compilation units that can be compiled separately from other modules. The C++ module system allows programmers to divide their code into individual pieces. It is not required to use modules in C++.

Still, they provide some benefits, including improved code organization and reduced compile time when the entire program isn’t recompiled when only one module changes.

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The programmer breaks the program into sections to avoid any complications within the code. The program has to use three segments
instead of one unit.

Calling Functions

Calling functions is a powerful programming technique that allows programmers to reuse code in their programs.

The main idea behind this technique is that it allows programmers to reuse code in their programs by using the same function name again and again.

It also makes it easier for programmers to maintain their code as they only need to change one function instead of many if there are any changes required.

int main(){
// Three calls of functions inside the main function.
//Call recieve_input() function
recieve_input();
//Call approach _input() function
approach_input();
//Call deliver_out() function
deliver_output();
return 0;
}

recieve_input(){
statement1
statement2
statement3
statement4
}

approach _input(){
statement1
statement2
statement3
statement4
}

deliver_output(){
statement1
statement2
statement3
statement4
}

C++ functions requirements

The programmer needs to understand some information about the function which he wants to build. These pieces of information are the following:

  • The specification code.
  • The information needed.
  • The value that the function returns.
  • Any errors that the function can return.
  • Function performance limits.

Example

The code of the program

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#include <iostream>
using namespace std;
//function declaration
int addition(int x,int y);
int main()
{
//Store number1
int number1;
//Store number2
int number2;
//Store the sum
int sum;
//Ask the user to choose number1
cout<<”Please, Enter your first score: “;
cin>>number1;
//Ask the user to choose number2
cout<<”Enter second score: “;
cin>>number2;
//The call of the function
sum=addition(number1,number2);
//Display the sum to the user
cout<<”Your final score is: “<<sum<<endl;
return 0;
}
//function definition
int addition(int x,int y)
{
return (x+y);
}

The output of the program

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Conclusion

In conclusion, we can see that a C++ function is a powerful tool for programming. It allows the programmer to create a program that does what they want.

  • A Functions can be defined as returning values or not returning values
  • A function can have only one return statement
  • A function can have any number of parameters
  • The body of the function is surrounded by curly braces { }
  • The body of a function contains statements that are executed when the function is called

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Sami Hamdi
Sami Hamdi

Written by Sami Hamdi

Hi, Your trainer, Sami Hamdi, helps you build your own Arduino projects. In the meantime, you will find the advanced C++ lessons https://full-skills.com/blog/