JavaScript Reflect.ownKeys() Method

The Reflect.ownKeys() method in Javascript is used to return an array of the target object’s own property keys and it ignores the inherited properties. 

Syntax:

Reflect.ownKeys( obj )

Parameters: This method accepts a single parameter as mentioned above and described below: 

• Obj: This parameter holds the target object and it is used to get its own keys.

Return value: This method always returns the Array of the target object’s own property keys.

Exceptions: A TypeError is an exception given as the result when the target is not an Object.

The below examples illustrate the Reflect.ownKeys() method in JavaScript:

Example 1: In this example, we will return the keys of the object using the Reflect.ownKeys() method in JavaScript.

javascript

<script>
    const object1 = {
      property1: 332,
      property2: 2
    };

    const array1 = [];

    console.log(Reflect.ownKeys(object1));

    console.log(Reflect.ownKeys(array1));

    const obj = {ab: 5, bc: 5};
    const obj1 = {ab: 5, bc: 5, ca:7};

    console.log(Reflect.ownKeys(obj));
    console.log(Object.keys(obj1));
    console.log(Reflect.ownKeys(obj1));
</script>

Output:

[ 'property1', 'property2' ]
[ 'length' ]
[ 'ab', 'bc' ]
[ 'ab', 'bc', 'ca' ]
[ 'ab', 'bc', 'ca' ]

Example 2: In this example, we will return the keys of the object using the Reflect.ownKeys() method in JavaScript.

javascript

<script>
    console.log(Reflect.ownKeys({z: 3, y: 2, x: 1}));
    console.log(Reflect.ownKeys([]));

    let sym = Symbol.for('comet')
    let sym2 = Symbol.for('meteor')
    let obj = {[sym]: 0, 'val': 0, '45': 0, 'sdf': 0,
               [sym2]: 0, 'safss': 0, '34': 0, 'val2': 0}
    console.log(Reflect.ownKeys(obj));

    var obj1 = Object.create({}, { hoo:
        { value: function() { return this.hoo; } } });
    console.log(Object.keys(obj1));
    console.log(Reflect.ownKeys(obj1));
</script>

Output:

[ 'z', 'y', 'x' ]
[ 'length' ]
[
  '34',
  '45',
  'val',
  'sdf',
  'safss',
  'val2',
  Symbol(comet),
  Symbol(meteor)
]
[]
[ 'hoo' ]

We have a complete list of Javascript Functions, to check those go through the Javascript Functions Complete Reference article.

Supported Browsers: The browsers supported by JavaScript Reflect.ownKeys() method are listed below: 

• Google Chrome 49 and above
• Edge 12 and above
• Firefox 42 and above
• Opera 36 and above
• Safari 10 and above