Used to determine whether an object has an own property with the specified property key.
The hasOwnProperty
method returns a boolean indicating whether
the object
has the specified property
. Does not attempt to fix known
issues in older browsers, but does ES6ify the method.
Kind: Exported function
Returns: boolean
- true
if the property is set on object
, else false
.
Throws:
TypeError
If object is null or undefined.
Param | Type | Description |
---|---|---|
object | Object |
The object to test. |
property | string | Symbol |
The name or Symbol of the property to test. |
Example
import hasOwnProperty from 'has-own-property-x';
const o = {
foo: 'bar',
};
console.log(hasOwnProperty(o, 'bar')); // false
console.log(hasOwnProperty(o, 'foo')); // true
hasOwnProperty(undefined, 'foo'); // TypeError: Cannot convert undefined or null to object