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' ]