builtin.js (1233B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MAIN // 22 23 /** 24 * Returns an array of an object's own enumerable property names. 25 * 26 * ## Notes 27 * 28 * - In contrast to the built-in `Object.keys()`, this function returns an empty array if provided `undefined` or `null`, rather than throwing an error. 29 * 30 * @private 31 * @param {*} value - input object 32 * @returns {Array} a list of own enumerable property names 33 * 34 * @example 35 * var obj = { 36 * 'beep': 'boop', 37 * 'foo': 3.14 38 * }; 39 * 40 * var k = keys( obj ); 41 * // e.g., returns [ 'beep', 'foo' ] 42 */ 43 function keys( value ) { 44 return Object.keys( Object( value ) ); 45 } 46 47 48 // EXPORTS // 49 50 module.exports = keys;