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What is Pure Functions JavaScript | Explained

What is Pure Functions Javascript

In this article, we will see what is pure functions javascript.

Javascript Function

A function is a block of code, meant to perform a specific task.
Whenever we want to perform some specific task, we create a function.

Why function? function is created

  • To divide a larger problem into smaller tasks or modules(manageability).
  • For reusability(i.e. once a function is defined, it can be used multiple times).
  • For abstraction(i.e hiding the way how tasks are done) (creating libraries).

Types of function

There are many ways in which we can create a function in javascript:

  • Function declaration
  • Function expression
  • Function constructor
  • IIFE ( Immediately Invokable Function Expression)

How to create a function using Function Declaration

A function defined with function declaration must begin with the function keyword.


function functionname([param1, param2, ...paramN]) // function header


A function without parameters and returning value

function display()

//output: Hi

Note: Every function gets executed only when we call them.

The syntax for calling the function:

functionname([param1, param2...paramN]);

Example : display();

If we call the function many times, the function is executed many times.

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