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Objects · medium

21. Objects: Computed Properties & Symbols

Dynamic keys, property attributes, and Symbol usage.

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Computed property syntax (`[expr]: val`) allows dynamic keys. `Symbol` primitives provide unique, non-colliding property keys.

js
const KEY = Symbol("id");
const obj = { [KEY]: 100, [computeName()]: "value" };

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  1. 1. What is guaranteed about Symbol() instances?

  2. 2. How do you define a property with a dynamic name?

  3. 3. Are Symbol-keyed properties included in Object.keys()?

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