Tutorial / Module 2

Functions Deep Dive

Declarations, parameters, hoisting, scope, closures, `this`, higher-order, pure functions — everything that makes functions the heart of JS.

2.1 JavaScript Function Declarations vs Expressions vs Arrows: When to Use Which Read 2.2 JavaScript Function Parameters and Arguments: Defaults, Rest, Destructuring Read 2.3 JavaScript Hoisting Explained: var, let, const, and Functions in 2026 Read 2.4 JavaScript Lexical Scope: How the Engine Resolves Every Variable Read 2.5 JavaScript Closures: The Definitive Guide (with 7 Production Patterns) Read 2.6 The JavaScript `this` Keyword: All 5 Binding Rules in One Place Read 2.7 JavaScript Higher-Order Functions and Composition: pipe() and compose() Read 2.8 JavaScript Pure Functions and Side Effects: The Gateway to Functional JS Read

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