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.

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).

Mar 22, 2025 · A function definition (also called a function declaration, or function statement) consists of the function keyword, followed by: The name of the function. A list of parameters to the function, enclosed in parentheses and separated by commas.

Mar 13, 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 the function body is reached.

Mar 19, 2023 · This post shows you six approaches to declare (aka define) JavaScript functions: the syntax, examples, and common pitfalls. Moreover, you will understand when to use a specific function type in certain circumstances.

The function statement declares a function. A declared function is "saved for later use", and will be executed later, when it is invoked (called). In JavaScript, functions are objects, and they have both properties and methods. A function can also be defined using an expression (See ).

What Are Function Declarations? A function declaration is the most common and straightforward way to define a function in JavaScript. It uses the function keyword followed by the name...

Nov 25, 2024 · JavaScript functions are declared using the function keyword, either as a declaration or expression. Declarations define named functions, while expressions assign functions to variables. Both enable code reuse and modularity. Syntax. Function Declarations. function functionName( parameters ) { // Statements }; Function Expressions

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

Apr 16, 2024 · In the following sections, we will delve deeper into the syntax, usage, and best practices of function declarations in JavaScript. We will also discuss the differences between function declarations and function expressions, explore the concept of hoisting, and provide real-world examples of function declarations.