javascript / intermediate
Snippet
Encapsulating Private Data with WeakMap
WeakMap allows associating private data with an object without exposing it via property keys. It also prevents memory leaks because entries are garbage-collected when the object is destroyed.
snippet.js
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const internalState = new WeakMap();class SecureVault {constructor(secret) {internalState.set(this, { secret });}getSecret() {return internalState.get(this).secret;}}
nodejs
Breakdown
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new WeakMap()
Initializes a collection where keys must be objects and are held weakly.
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internalState.set(this, ...)
Maps the current instance to a private data object.