What does "const" mean in programming?

const is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.

Definition

A keyword that declares a block-scoped variable whose binding cannot be reassigned after initialization. The value itself may still be mutable (e.g. you can push to a const array).

Example

"const MAX_RETRIES = 3; // the binding MAX_RETRIES cannot be reassigned"

Related terms

let
var
variable
constant

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