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Version: 3.13.0

handler.ownKeys()

The handler.ownKeys() method is a trap for Reflect.ownKeys().

Syntax​

new Proxy(target, {
  ownKeys(target) {
  }
});

Parameters​

The following parameter is passed to the ownKeys() method. this is bound to the handler.

  • target
    • : The target object.

Return value​

The ownKeys() method must return an enumerable object.

Description​

The handler.ownKeys() method is a trap for Reflect.ownKeys().

Interceptions​

This trap can intercept these operations:

Or any other operation that invokes the [[OwnPropertyKeys]] internal method.

Invariants​

If the following invariants are violated, the trap throws a TypeError when invoked.

  • The result of ownKeys() must be an array.
  • The type of each array element is either a String or a Symbol.
  • The result List must contain the keys of all non-configurable own properties of the target object.
  • If the target object is not extensible, then the result List must contain all the keys of the own properties of the target object and no other values.