Reflect.deleteProperty()

The Reflect.deleteProperty() static method is like the delete operator, but as a function. It deletes a property from an object.

Try it

const object = {
  foo: 42,
};

Reflect.deleteProperty(object, "foo");

console.log(object.foo);
// Expected output: undefined

const array = [1, 2, 3, 4, 5];
Reflect.deleteProperty(array, "3");

console.log(array);
// Expected output: Array [1, 2, 3, <1 empty slot>, 5]

Syntax

Reflect.deleteProperty(target, propertyKey)

Parameters

target

The target object on which to delete the property.

propertyKey

The name of the property to be deleted.

Return value

A boolean indicating whether or not the property was successfully deleted.

Exceptions

TypeError

Thrown if target is not an object.

Description

Reflect.deleteProperty() provides the reflective semantic of the delete operator. That is, Reflect.deleteProperty(target, propertyKey) is semantically equivalent to:

delete target.propertyKey;

At the very low level, deleting a property returns a boolean (as is the case with the proxy handler). Reflect.deleteProperty() directly returns the status, while delete would throw a TypeError in strict mode if the status is false. In non-strict mode, delete and Reflect.deleteProperty() have the same behavior.

Reflect.deleteProperty() invokes the [[Delete]] object internal method of target.

Examples

Using Reflect.deleteProperty()

const obj = { x: 1, y: 2 };
Reflect.deleteProperty(obj, "x"); // true
console.log(obj); // { y: 2 }

const arr = [1, 2, 3, 4, 5];
Reflect.deleteProperty(arr, "3"); // true
console.log(arr); // [1, 2, 3, <1 empty slot>, 5]

// Returns true if no such property exists
Reflect.deleteProperty({}, "foo"); // true

// Returns false if a property is unconfigurable
Reflect.deleteProperty(Object.freeze({ foo: 1 }), "foo"); // false

Specifications

Browser compatibility

See also

• Polyfill of Reflect.deleteProperty in core-js
• Reflect
• delete
• handler.deleteProperty()