WeakSet.prototype.has() - JavaScript | MDN

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non-registered symbol

Returns true if the specified value exists in the WeakSet object; otherwise false. Always returns false if value is not an object or a non-registered symbol.

WeakSet.prototype.add()

WeakSet.prototype.delete()

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This page was last modified on Sep 22, 2025 by MDN contributors.

[Symbol.hasInstance]()

__defineGetter__()

__defineSetter__()

__lookupGetter__()

__lookupSetter__()

propertyIsEnumerable()

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