Execution Context & Hoisting

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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 Questions4

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

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

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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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