A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses (). Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).

Jul 8, 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. To use a function, …

Jun 28, 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.

Summary Use the function keyword to declare a function. Use the functionName() to call a function. All functions implicitly return undefined if they don’t explicitly return a value. Use the return statement to return a value from a function explicitly. The arguments variable is an array-like object inside a function, representing function ...

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.

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.

Jun 30, 2022 · By Chinwendu Enyinna 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. As a …

JavaScript functions are defined with the function keyword. You can use a function declaration or a function expression.

JavaScript functions are reusable blocks of code that perform a specific task, taking some form of input and returning an output. To define a function, you must use the function keyword, followed by a name, followed by parentheses ( ).

Jul 15, 2025 · The function* declaration creates a binding of a new generator function to a given name. A generator function can be exited and later re-entered, with its context (variable bindings) saved across re-entrances.