JavaScript Reflect ownKeys() Method

JaScript 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.

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.

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)); 

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.

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));

let obj1 = Object.create({}, {
    hoo:
        { value: function () { return this.hoo; } }
});
console.log(Object.keys(obj1));
console.log(Reflect.ownKeys(obj1));

Output:

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

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

We have a complete list of Javascript Reflects methods, to check those go through the JavaScript Reflect Reference article.