Introduction
C++ is a general-purpose programming language that supports procedural, object-oriented, and generic programming. C++ provides a lot of flexibility to programmers.
The article will explain all about C++ Function Definition. Study the subject from all angles as the concept becomes simple and applicable in uncomplicated programming codes.
C++ Function Definition
Naming C++ functions
Naming C++ functions is essential to avoid confusion and make the code readable. There are a few tips for naming functions:
- Keep the name short but descriptive
- Give a hint about what the function does or what it returns.
- Use verbs when possible.
C++ functions parameter
A parameter is an input to a function.The name of the parameter is written in front of the type.Commas separate parameters.The argument is the value that will be passed to a function.It can be any type, including character strings, numbers, and objects.
int sum(int x, int y) { return x + y; }
C++ functions return types
A function is a block of code that the computer can execute. It has a specific input and output. The input is called parameters, and the result is called return type.The return type of a function is an expression that evaluates a value.There are three types of return types:
- void – if there will be no value returned,
- int – if the function will always return an integer,
- double – if the function always returns a double.
C++ function syntax with no parameters
A function is a block of code that can be executed by running it. Functions in C++ can have no parameters, or they can have one or more parameters.A function without any parameters is just a block of code that needs to be executed. For example, we could create an empty function and run it by using the following syntax:int myFunction() {statementsreturn0;}The C++ function without parameters needs to have the following entries:
C++ function syntax with no parameters
The nameTwo parentheses with no parametersReturn typeBody
C++ function syntax with one parameters
The C++ language supports the definition of functions that can take parameters. The syntax for defining a function with one parameter is as follows:
- Function name
- Parentheses containing the parameters to be passed to the function.
- A return statement specifies the type of data the function returns. If no data is returned, then void should be used.
- The code for performing any action required by the function’s purpose.
The following is a C++ function with one parameter.int sum(int x) {//returns the sum of two integers, x, and y.return x + y;}
The C++ function without parameters needs to have the following entries:
C++ function syntax with one parameters
The nameTwo parentheses with one parameterReturn type Body
C++ function syntax with two parameters
Functions are used to encapsulate code blocks to make them reusable and help avoid duplication of code when it needs to be called more than once. Functions can be created using function declarations or by using function expressions. The syntax for declaring a function with two parameters would be:int func(int x, int y) {//returns the product of two integers, x, and y}The C++ function without parameters needs to have the following entries:
C++ function syntax with two parameters
The nameTwo parentheses with two parameters
Return type Body
C++ function without return type
A C++ function without a return type is a function that does not return any data from the function. This can be done by using the keyword void.When creating a C++ function without a return type, you must use the keyword void in the declaration. The syntax for declaring this is as follows:
void myFunction(){Statementsreturn; // optional}
The C++ function without parameters needs to have the following entries:
C++ function without return type
The nameTwo parentheses with two parametersWithout return typeBody
C++ function without either return type and parameters
The C++ function without either return type or parameters is a function that does not have a return type or parameters. The only thing that the function does is to print “Hello friends.” to the console.This effortless program prints “Hello friends.” to the console. This program doesn’t have any return type or parameters.
int main() {cout<<“Hello friends.”<<endl;}
C++ function without return type and with multiple parameters
The following is the simplest way to create a C++ function without the return type and with multiple parameters. The parameter list should be enclosed in parentheses, followed by a comma, followed by the function’s body.
void myFunction(int b, int c){Statementsreturn; // optional}
Calling a function
The concept of calling a function
In programming, functions are a way to break code into smaller pieces. Functions are a way to reuse code and make it easier to debug. Functions can be called from anywhere in the program without repeatedly rewording the same code.Functions can take parameters, which is information they need before doing their job. The function will use these parameters when it is called.The concept of calling a function is straightforward. It’s just referring to a function by name, then providing the parameters needed for it to complete its task.
Calling C++ function syntax
The code of the program
#include <iostream>using namespace std;void new_day(){cout<<” Good morning”<<endl;}int main(){new_day();return 0;}
The output of the program
Calling C++ function syntax second model
The code of the program
#include <iostream>using namespace std;void evening_greetings(){cout<<” Goodevening”<<endl;}void say_welcome(){cout<<” You are welcome”<<endl;evening_greetings();}int main(){evening_greetings();say_welcome();cout<<“Welcome here is main”<<endl;return 0;}
The output of the program
Not called before it is defined
The compiler must know the function before calling it.The compiler must thoroughly understand the function and its parameters before it is called.The information that must know about the function is the following:
The compiler can only execute what it knows about, so if there is a function it does not understand, it will not be able to call that function.
Conclusion
A function definition specifies a function’s name, return type, parameters, and body.Function definitions are typically placed at the start of a source file, but they may appear anywhere within the file.The syntax for declaring a function follows this pattern:
return_type name (parameter list) { // Function body}
C++ function is a function that can be called from the C++ language.
#include <iostream>using namespace std;void new_day(){cout<<” Calling a C++ function”<<endl;}int main(){new_day();return 0;}
