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How does variable hoisting affect the value of variables in JavaScript?
Asked on Apr 29, 2026
Answer
In JavaScript, variable hoisting is a behavior where variable declarations are moved to the top of their containing scope during the compile phase. This means you can use variables before they are declared, but their values are not hoisted.
<!-- BEGIN COPY / PASTE -->
console.log(myVar); // Output: undefined
var myVar = 5;
console.log(myVar); // Output: 5
<!-- END COPY / PASTE -->Additional Comment:
✅ Answered with JavaScript best practices.- In the example, "myVar" is hoisted to the top of its scope, so the first console.log does not throw an error but outputs "undefined".
- The assignment of the value "5" to "myVar" occurs after the first console.log, so the second console.log outputs "5".
- Only the declaration is hoisted, not the initialization.
- Let and const declarations are also hoisted, but they are not initialized until their definition is evaluated, leading to a "Temporal Dead Zone" if accessed before initialization.
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