JavaScriptEasy
What is the difference between a Map object and a plain object in JavaScript?
By FrontendPro Editorial Team Updated 8/8/2026
#JavaScript
Answer
Both Map objects and plain objects in JavaScript can store key-value pairs, but they have several key differences:
| Feature | Map | Plain object |
|---|---|---|
| Key type | Any data type | String (or Symbol) |
| Key order | Maintained | Not guaranteed |
| Size property | Yes (size) | None |
| Iteration | forEach, keys(), values(), entries() | for...in, Object.keys(), etc. |
| Inheritance | No | Yes |
| Performance | Generally better for larger datasets and frequent additions/deletions | Faster for small datasets and simple operations |
| Serializable | No | Yes |
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