该函数接收一个字符串参数,并返回对应的枚举值。例如,我们创建一个函数 getEnumValue: 代码语言:txt 复制 function getEnumValue(str: string): Color | undefined { const keys = Object.keys(Color).filter(key => isNaN(Number(key))); const values = keys.map(key => Color[key as keyof type...
假设定义了一个这样的枚举类型: enum MyEnum { aa = 1, bb = 2 } 1、字符串转换为枚举: string strA...= "aa"; MyEnum myEnum = (MyEnum)Enum.Parse(typeof(MyEnum), strA); 上面的方法是区分大小写的,也就是说,如果strA的值为“AA...aa"; MyEnum myEnum = (MyEnum)Enum.Parse(typeof(...
: string public name: string = '张三' // public 关键字 可不写 // name: string = '张三' getId() { return this.id } getName() { return } } // 继承 class List extends User { getName() { return } } const user = new User // user.id = 1000 console.log(); // 张三 console...
string test = TestEnum.Test1.ToString(); //这句话是否发生装箱操作 3.2.1 内部原理 首先查看枚举中的ToString方法,这里重写了ToString方法 public override stringToString() { return InternalFormat((RuntimeType) base.GetType(), this.GetValue());} 查看InternalFormat方法的实现 private static string Inter...
function getLocalizedStatusText(status: Status, lang: 'en' | 'zh'): string { const map = lang === 'en' ? statusTextMapEN : statusTextMapZH; return map[status] || 'Unknown'; } 5. 无法扩展自定义属性 如果需要为枚举项添加额外属性(如图标、颜色、权限等),原生 enum 无法满足: ...
而enum 的缺点,就是在一开始提到的:违背了 TypeScript = JavaScript + Types 的构想 比如下面的这段 TS 代码: type DataItem ={ label:string; value: number|string; }; function formatLabels(arr: DataItem[]) {returnArray.isArray(arr) ? arr.map((x) => x.label).join(',') :''; ...
}//number enumenumDirection{Up=1,Down,Left,Right}// TypeScript enum 枚举实现原理,反向映射// Direction ={// 1: "Up", 2: "Down", 3: "Left", 4: "Right",// Up: 1, Down: 2, Left: 3, Right: 4,// }logString(Level.A);logNumber(Direction.Down);logNumber(Roles.Admin);// con...
String enums allow you to give a meaningful and readable value when your code runs, independent of the name of the enum member itself. 自增而来的失去了可读性,所以不支持自增。同理,字符串枚举值本就可读,不再需要反向映射: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 var Direction; (fun...
Enums come in two flavors string and numeric. Lets start with numeric.Numeric Enums - DefaultBy default, enums will initialize the first value to 0 and add 1 to each additional value:ExampleGet your own TypeScript Server enum CardinalDirections { North, East, South, West } let current...