JS Practice — Built-in Objects

Proxy deleteProperty trap — return false

📖 Usage Example

const log = []
const p = new Proxy({}, {
  deleteProperty: (t, k) => { log.push(k); return true }
})
delete p.foo
console.log(log) // → ['foo']

The deleteProperty trap intercepts delete operations, allowing custom logic when a property is deleted from a proxy.

deleteProperty trap returning false

When the deleteProperty trap returns false, the delete expression evaluates to false and the property is not removed.

Challenge: Verify that delete p.x returns false when the trap returns false.

💡 Hints (1)

• Returning `false` from `deleteProperty` prevents deletion and makes `delete` evaluate to `false`.