A JavaScript function is a block of code designed to perform a particular task. A JavaScript function is executed when "something" invokes it (calls it).

This tutorial introduces you to JavaScript functions that structure your code into smaller reusable units.

Oct 14, 2022 · Functions are the main “building blocks” of the program. They allow the code to be called many times without repetition. We’ve already seen examples of built-in functions, like alert(message), prompt(message, default) and confirm(question). But we can create functions of our own as well. Function Declaration

Mar 22, 2025 · Functions are one of the fundamental building blocks in JavaScript. A function in JavaScript is similar to a procedure—a set of statements that performs a task or calculates a value, but for a procedure to qualify as a function, it should take some input and return an output where there is some obvious relationship between the input and the output.

Apr 15, 2025 · Functions in JavaScript are reusable blocks of code designed to perform specific tasks. They allow you to organize, reuse, and modularize code. It can take inputs, perform actions, and return outputs. A function definition is sometimes also termed a function declaration or function statement.

Explore the basics of functions in JavaScript, including anonymous and arrow functions, and learn how to organize your code using functions.

The most common way to define a function in JavaScript is by using the function keyword, followed by a unique function name, a list of parameters (that might be empty), and a statement block surrounded by curly braces.

A function is an independent block of code that performs a specific task. A function expression is a way to store functions in variables. In this tutorial, you will learn about JavaScript functions and function expressions with the help of examples.

In this tutorial you will learn how to define and call a function in JavaScript. What is Function? A function is a group of statements that perform specific tasks and can be kept and maintained separately form main program.

JavaScript functions are defined with the function keyword. You can use a function declaration or a function expression. Earlier in this tutorial, you learned that functions are declared with the following syntax: Declared functions are not executed immediately.