C Functions

A function is a segment of code that executes only upon invocation.

It accepts input data, referred to as parameters.

Functions serve to execute specific tasks and are vital for code reuse: Define the logic once and employ it repeatedly.

Predefined Functions

Indeed, it appears you’re already familiar with the concept of a function. Throughout this tutorial, you’ve been utilizing functions consistently.

As an illustration, “main()” serves as a function responsible for executing code, while “printf()” functions to output or print text onto the screen.

Example

Create a Function

To create, commonly referred to as declare, your own function, indicate the function name, followed by parentheses () and curly brackets {}.

Syntax

Example Explained

• The functin iso named myFunction().
• “void” indicates that the function does not return a value. Further details about return values will be covered in the upcoming chapter.
• Within the function body, include code that specifies the actions the function should perform.

Call a Function

Declared functions are not executed immediately. Instead, they are “stored for later use” and will be executed only when they are called.

To invoke a function, simply write the function’s name followed by two parentheses () and a semicolon ;

In the given example, myFunction() is employed to print a text (the action) upon its invocation.

Example

Within the main function, invoke myFunction().

A function can be invoked multiple times.

Example