WeakMap in JavaScript

What this snippet does

WeakMap holds weak references — when the key object is GC'd, the entry disappears automatically with no memory leak.

Expected output

{ role: 'admin', loginCount: 5 }
user cleared

Why practise typing this

Typing weakmap code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.

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