Functions in JavaScript

Functions are the "first-class citizens" of JavaScript. They can be stored in variables, passed into other functions, and returned from functions.

1. Function Declaration

Traditional functions that are hoisted.

function greet(name) {
  return `Hello, ${name}`;
}

2. Function Expression

Assigning a function to a variable. These are not hoisted.

const greet = function(name) {
  return `Hello, ${name}`;
};

3. Arrow Functions

Modern shorthand that has a lexical this binding.

const greet = (name) => `Hello, ${name}`;

4. Higher-Order Functions

Functions that operate on other functions (either taking them as arguments or returning them).

• Examples: .map(), .filter(), .reduce().

5. Callback Functions

A function passed into another function as an argument, to be executed later.

Next Step: Prepare for Interview Questions.