How to Create Function in C++?

Let's look at the function that we created in the previous chapter:

main

#include <iostream>

// Function to calculate the factorial of an integer

int calculateFactorial(int n)

{

int factorial = 1;

for (int i = 1; i <= n; i++)

factorial *= i;

return factorial;

}

int main()

{

// Call the calculateFactorial function and print the result

std::cout << calculateFactorial(5) << std::endl;

std::cout << calculateFactorial(8) << std::endl;

}


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#include <iostream>

// Function to calculate the factorial of an integer
int calculateFactorial(int n)
{
    int factorial = 1;
    for (int i = 1; i <= n; i++)
        factorial *= i;
    return factorial;
}

int main()
{
    // Call the calculateFactorial function and print the result
    std::cout << calculateFactorial(5) << std::endl;
    std::cout << calculateFactorial(8) << std::endl;
}

Function signature: Provides essential information about a function's interface, including its name, return type, and parameter list.
- Return type: Specifies the type of data the function will return. In this example, it's int, indicating an integer will be returned.
- Function name: Unique identifier for the function, used to call it from other parts of the program. Our function is named calculateFactorial.
Parameter list: Defines the input values the function expects. This function expects a single integer parameter named n.
Function Body: Contains the code that performs the desired operations, enclosed in curly braces {}. In this example, the function calculates the factorial of n using a for loop and stores the result in the factorial variable.
Return Statement: Specifies the value the function will return to the caller. In this case, it returns the calculated factorial value using the return keyword.

Thus, above, we described the structure of a function in C++: any function consists of a signature, a function body, and a return value.

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Section 1. Chapter 2