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).

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.

What is a Function? A function holds a piece of code that does a specific task. A function takes some data as input, the code inside the function does something with the data, and then the result is returned. Click the "Run" button below to see the function converting a temperature from Fahrenheit to Celsius.

Apr 15, 2025 · In this article we'll explore fundamental concepts behind functions such as basic syntax, how to invoke and define them, scope, and parameters. An understanding of HTML and the fundamentals of CSS, familiarity with JavaScript basics as covered in previous lessons.

Jun 30, 2022 · Functions are one of the fundamental concepts in programming. They let us write concise, modular, reusable, and maintainable code. They also help us obey the DRY principle when writing code. In this article, you will learn what functions are in JavaScript, how to write your own custom functions, and how to implement them.

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. To create a function we can use a function declaration.

Learn about the different types of functions in JavaScript, including function declaration, Function Expression, Arrow function, IIFEs, Generator Function, Async Function, and Constructor Function.

Mar 31, 2024 · A function is a modular, reusable block of statements used to perform a set of related tasks, such as calculating and returning a value based on arguments provided to the function. As with all non-primitive values, functions are objects.

Functions allow us to encapsulate a block of code and reuse it multiple times. Functions make JavaScript code more readable, organized, reusable, and maintainable. In JavaScript, a function can be defined using the function keyword, followed by the name of a function and parentheses.