Reflect.deleteProperty() - JavaScript | MDN
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
js
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
targetis not an object.
Description
Reflect.deleteProperty() provides the reflective semantic of the delete operator. That is, Reflect.deleteProperty(target, propertyKey) is semantically equivalent to:
js
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()
js
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
| Specification |
|---|
| ECMAScript® 2027 Language Specification # sec-reflect.deleteproperty |