如下所示的代码中,我定义了一些常量。我想使用Symbol
来确保每个常量都是唯一的。但是当我使用以下代码行时:
if (isBtnDigitizePolygonClicked.value == true) { return polygDigiConstants.CONST_STRING_DIGITIZE; }
上述代码返回的值是Symbol('Digitize')
,但我期望它是Digitize
,如本教程所述:https://www.scaler.com/topics/enum-in-javascript/
教程内容:
const Direction = Object.freeze({ North: Symbol('north'), East: Symbol('east'), West: Symbol('west'), South: Symbol('south'), }) const Pole = Object.freeze({ North: Symbol('north'), South: Symbol('south'), }) console.log(Direction.North === Pole.North) 上述代码的输出为: false
请告诉我如何正确使用Symbol
来定义属性。
polygDigiConstants.js
function define(name, value) { Object.defineProperty(polygDigiConstants, name, { value: value, enumerable: true, writable: false, }); } export let polygDigiConstants = {}; define('CONST_STRING_DIGITIZE', Symbol('Digitize')); define('CONST_STRING_STOP_DIGITIZE', Symbol('Stop')); define('CONST_STRING_CLEAR_DIGITIZED', Symbol('Clear'));
polygDigiConstants.js
JS
polygDigiConstants.CONST_STRING_DIGITIZE将直接给你字符串'Digitize'。