JS Practice — Built-in Objects

Proxy deleteProperty trap — passthrough

📖 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 — no trap

Without a deleteProperty trap, delete forwards to the target and actually removes the property.

Challenge: Verify that after delete p.x, p.x is undefined.

💡 Hints (1)