What does "map" mean in programming?

map 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 collection that stores key-value pairs where each key is unique. You look up values by key in O(1) average time. In JavaScript the built-in Map object preserves insertion order and allows any type as a key.

Example

"const scores = new Map<string, number>(); scores.set('Alice', 95);"

Related terms

dictionary
set
array
object
key

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