JS Built-ins
← Reflect12 / 140
Reflecthasbeginner

Reflect.has() — missing key returns false

📖 Usage Example
const obj = { a: 1 }
console.log(Reflect.has(obj, 'a'))  // → true
console.log(Reflect.has(obj, 'b'))  // → false
// Equivalent to: 'a' in obj

Reflect.has() checks whether an object has a property, equivalent to the in operator.

Reflect.has() — missing key

When the key does not exist in the object or its prototype chain, Reflect.has() returns false.

Challenge: Verify that Reflect.has({}, 'missing') returns false.

💡 Hints (1)
  • • `Reflect.has` returns `false` for keys that do not exist on the target or its prototype chain.