typescript enum字符串 动态取值 We have to represent every bit of data in numerical values to be processed and analyzed by machine learning and deep learning models. However, strings do not usually come in a nice and
Enums can also contain strings. This is more common than numeric enums, because of their readability and intent.Example enum CardinalDirections { North = 'North', East = "East", South = "South", West = "West" }; // logs "North" console.log(CardinalDirections.North); // logs "West...
AI代码解释 enumFlexDirection{Row,Column}constdirection=FlexDirection.Column;// 推断类型: FlexDirection.Column 注意,direction类型为FlexDirection.Column,它是枚举字面量类型。如果使用let或var关键字来声明direction变量,那么它的推断类型应该是FlexDirection。 更好的只读属性推断 与局部const变量类似,带有字面量初始...
相反,使用keyof typeof获取将所有 Enum 键表示为字符串的类型。 enum LogLevel { ERROR, WARN, INFO, DEBUG, } /** * This is equivalent to: * type LogLevelStrings = 'ERROR' | 'WARN' | 'INFO' | 'DEBUG'; */ type LogLevelStrings = keyof typeof LogLevel; function printImportant(key: Log...
enum Direction {Up = 'UP',Down = 'DOWN'} 1. any类型 不推荐使用any 当值类型为any时,就失去TS特性 let obj: any = 123 1. TS中的typeof TS中既可以按照JS的方式使用typeof,还可以在类型上下文中使用 let p = {x:1,y:2} function formatPoint(point: typeof p){} ...
String enums are serializable over transfer protocols and are easily debuggable — they are just strings, after all. They also allow for a meaningful and readable value at runtime, independent of the name of the enum member. For completely string-based enums, we cannot omit any initializers,...
enum LogLevel { ERROR, WARN, INFO, DEBUG,} /** * 这相当于: * type LogLevelStrings = 'ERROR' | 'WARN' | 'INFO' | 'DEBUG'; */type LogLevelStrings = keyof typeof LogLevel;function printImportant(key: LogLevelStrings, message: string) { const num = LogLevel[key]; ...
As of TypeScript 2.4, it is now possible to define string enums, or more precisely, enums with string members. Just like any other numeric enum, string enums can be made constant using theconstmodifier so that they disappear entirely from the generated JavaScript; in this case, all enum ...
Enum 类型是对 JavaScript 标准数据类型的一个补充。 像C#等其它语言一样,使用枚举类型可以为一组数值赋予友好的名字。 enum Color { Red = 8, Green, Blue, } // 默认0,1,2 let c: Color = Color.Green; let cName: string = Color[9]; console.log(c); console.log(cName); // 9 // Green ...
enum Direction { Up = 'Up', Down = 'Down', Left = 'Left', Right...= 'Right' } console.log(Direction['Right'], Direction.Up); // Right Up 如果设定了一个变量为字符串之后,后续的字段也需要赋值字符串...即将数字枚举和字符串枚举结合起来混合起来使用,如下: enum BooleanLikeHeterogeneousEnum...