Functions in C Language

A function is a block of code that performs a specific task. It is a group of statements that together perform a task.

In this tutorial, you will be introduced to functions (both user-defined and standard library functions) in C programming.

In C, we can divide a large program into the basic building blocks known as function.

The function contains the set of programming statements enclosed by {}.

Dividing a complex problem into smaller chunks makes our program easy to understand and reuse.

A function can be called multiple times to provide reusability and modularity to the C program.

Every C program has at least one function, which is main(), and all the most trivial programs can define additional functions. The execution of a C program begins from the main() function.

Types of function

There are two types of function in C programming as mentioned below.

  1. Standard library functions
  2. User-defined functions

Standard library functions

The standard library functions are built-in functions in C programming.

These are the functions which are declared in the C header files such as scanf(), printf(), gets(), puts(), ceil(), floor() etc.

User-defined function

These are the functions which are created by the C programmer.

This is just an overview of functions. You will learn everything about functions in C in next chapters of this tutorial.