Execution Context & Hoisting

Difficulty: medium

Overview

Each function call creates an Execution Context pushed onto the Call Stack. The Global Execution Context runs first. During the creation phase, var declarations and function declarations are hoisted — var is initialised to undefined; function declarations are fully hoisted. let and const are hoisted but remain in the Temporal Dead Zone (TDZ) until their declaration line, causing a ReferenceError if accessed early.

Practice Linked Questions

medium

Q1. What is the output? ```js for (var i = 0; i < 3; i++) {} console.log(i); ```

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medium

Q2. What is the output? ```js console.log(foo); var foo = "bar"; ```

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medium

Q3. What happens when you access a `let` variable before its declaration?

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Q4. What is the Call Stack in JavaScript?

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