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). Example

6 days ago · 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.

A function is an independent block of code that performs a specific task, while a function expression is a way to store functions in variables. Here's a quick example of function and function expression.

Jul 11, 2024 · JavaScript Function Examples A function in JavaScript is a set of statements that perform a specific task. It takes inputs, and performs computation, and produces output.

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.

Sep 7, 2021 · Functions are a set of of organised instructions that correspond to a certain task or specific functionality a user wants to implement in their program to achieve a single desired outcome. The code inside a function runs only when it is needed, meaning only when it is called.

Oct 14, 2022 · 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. To create a function we can use a function declaration. It looks like this: function showMessage() { alert( 'Hello everyone!' ); }

JavaScript provides many built-in functions such as parseInt() and parseFloat(). In this tutorial, you will learn how to develop custom functions. To declare a function, you use the function keyword, followed by the function name, a list of parameters, and the function body as follows: // function body // ...

Declare a function that outputs "Hello World" when it is called: document.getElementById("demo").innerHTML = "Hello World!"; More examples below. The function statement declares a function. A declared function is "saved for later use", and will be executed later, when it is invoked (called).

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