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ControlFlowintermediate

Control Flow — for...in: iterate over object keys

for...in iterates enumerable property keys

for...in iterates over all enumerable string keys of an object (own + inherited). Usually combined with hasOwnProperty for safety.

Challenge: Write collectOwnKeys(obj) that returns a sorted array of the object's own enumerable keys using for...in + hasOwnProperty.

💡 Hints (1)
  • • Use Object.prototype.hasOwnProperty.call(obj, key) to skip inherited properties