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Js Variables Let Const — Free Javascript Tutorial

Learn Js Variables Let Const in Javascript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

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TL;DR: Learn Js Variables Let Const in Javascript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated Jul 14, 2026

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Js Variables Let Const in Javascript

`var` is the old way to declare variables — it is function-scoped and hoisted (moved to the top internally). Avoid `var` in modern code.

`let` is block-scoped. It can be reassigned but not re-declared in the same scope. Use `let` for values that change.

`const` is block-scoped. It CANNOT be reassigned. Use `const` by default — change to `let` only when needed. `const` for objects/arrays doesn't make the contents immutable, just the binding.

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