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).

Jul 8, 2025 · 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.

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.

JavaScript Functions Summary: in this tutorial, you will learn about JavaScript functions and how to use them to structure the code into smaller and more reusable units.

Oct 14, 2022 · The function keyword goes first, then goes the name of the function, then a list of parameters between the parentheses (comma-separated, empty in the example above, we’ll see examples later) and finally the code of the function, also …

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 · In this article, you learned what functions in JavaScript are all about and how you can write your own functions. With functions, you can organize your code by grouping everything into separate blocks that perform different tasks.

Jul 10, 2025 · The Function object provides methods for functions. In JavaScript, every function is actually a Function object.

Read our JavaScript Tutorial to learn all you need to know about functions. Start with the introduction chapter about JavaScript Functions and JavaScript Scope. For more detailed information, see our Function Section on Function Definitions, Parameters, Invocation …

An anonymous function in JavaScript is a function that is not given a name. Instead, it is usually used where a function is expected as an argument, such as in a callback function or an event handler.

Jul 23, 2025 · In JavaScript, functions are blocks of reusable code designed to perform a specific task. Understanding how to declare and invoke (call) functions is fundamental to writing efficient and maintainable code. Function Declaration is the process of defining a function with a specific name and logic, allowing it to be reused throughout your program.

Mar 11, 2023 · Discover the power of functions in JavaScript with this comprehensive chapter. Learn how to define and call functions, return values, and use function expressions. Take your programming skills to the next level with this beginner-friendly guide.

Jul 9, 2025 · In this article we'll explore fundamental concepts behind functions such as basic syntax, how to invoke and define them, scope, and parameters.

Want to learn all about JavaScript functions? Learn how to write a function, how to use it, and why you should use them in your JavaScript code today!

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 18, 2024 · Learn how to create a JavaScript function, then publish the local Node.js project to serverless hosting in Azure Functions using the Azure Functions extension in Visual Studio Code.

Jan 20, 2023 · In this article, we have covered the basics of functions in JavaScript, including how to define, call, and use them in our codes. With a solid understanding of functions, you can write more efficient and maintainable code in JavaScript.

6 days ago · Discover what a JavaScript constructor is, how to create and use constructor functions and classes, and when to use them for object creation in modern JS.

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

Jul 8, 2025 · In JavaScript, functions are first-class objects, because they can be passed to other functions, returned from functions, and assigned to variables and properties.

Jul 8, 2025 · A function declaration creates a Function object. Each time when a function is called, it returns the value specified by the last executed return statement, or undefined if the end of …

Jul 8, 2025 · The main difference between a function expression and a function declaration is the function name, which can be omitted in function expressions to create anonymous functions.

1 day ago · The await using declaration declares block-scoped local variables that are asynchronously disposed. Like const, variables declared with await using must be initialized and cannot be reassigned. The variable's value must be either null, undefined, or an object with an [Symbol.asyncDispose]() or [Symbol.dispose]() method. When the variable goes out of scope, …