New programmers · 7 min
Variables and values
Store values with const and let, and choose a declaration based on whether reassignment is needed.
Choose between const and let, and predict the value held by a variable after reassignment.
A name for a value
A variable gives a value a name so you can use it later. Prefer const when the binding will not be reassigned.
Example
const courseName = 'JavaScript';
When a value must change
Use let when you need to reassign the variable. The new value must still follow the language’s type and syntax rules.
Example
let score = 0; score = score + 1;
Bindings and objects
const prevents reassignment of the binding, but it does not make an object’s properties immutable.
Example
const learner = { name: 'Asha' }; learner.name = 'Ravi';
Knowledge check
Try it yourself
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About this lesson
Source: Original GyanStudio learning material. Editorial review pending. Last updated 5 November 2026.
This learning preview is not an official exam notice or a substitute for checking the relevant authority’s current information.