JavaScript Core Concepts Explained: Variables, Closures, Scope and More

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A developer learning guide published on DEV Community breaks down essential JavaScript fundamentals covered in a third-week study session. The article explains key concepts including variable declarations using var, let, and const, hoisting behavior, and how the JavaScript engine processes code through execution context and the call stack. It also covers lexical scope and the scope chain, describing how inner functions can access variables from their outer functions, a mechanism that enables closures. Additional topics include the this keyword, and clean coding principles such as DRY and KISS. The guide is aimed at beginner developers seeking to understand what happens behind the scenes when JavaScript code runs.

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