keys

Object Keys

Return an array of an object's own enumerable property names.

Usage

var objectKeys = require( '@stdlib/utils/keys' );

objectKeys( obj )

Returns an array of an object's own enumerable property names.

var obj = {
    'a': 1,
    'b': 2
};

var keys = objectKeys( obj );
// e.g., returns [ 'a', 'b' ]

Notes

• Name order is not guaranteed, as object key enumeration is not specified according to the ECMAScript specification. In practice, however, most engines use insertion order to sort an object's keys, thus allowing for deterministic extraction.
• In contrast to the built-in Object.keys(), if provided null or undefined, the function returns an empty array, rather than throwing an error.

Examples

var objectKeys = require( '@stdlib/utils/keys' );

function Foo() {
    this.beep = 'boop';
    this.a = {
        'b': 'c'
    };
    return this;
}

Foo.prototype.foo = [ 'bar' ];

var obj = new Foo();
var keys = objectKeys( obj );

console.log( keys );
// e.g., => [ 'beep', 'a' ]

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See Also

• @stdlib/utils/entries: return an array of an object's own enumerable property key-value pairs.
• @stdlib/utils/keys-in: return an array of an object's own and inherited enumerable property names.
• @stdlib/utils/nonindex-keys: return an array of an object's own enumerable property names which are not integer indices.
• @stdlib/utils/values: return an array of an object's own enumerable property values.