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 clean format and require a lot preprocessing. 我们必须以数值表示数据的每一位...
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...
//(enum member) EDirection.Up = 0 ODirection.Up; //(property) Up: 0 // 使用枚举作为参数 function walk(dir: EDirection) {} // 需要一个额外的引出钥匙 type Direction = typeof ODirection[keyof typeof ODirection]; function run(dir: Direction) {} walk(EDirection.Left); run(ODirection....
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...
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 ...
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 ...
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,...
Check outConvert String to Enum in TypeScript Check Substrings and String Content This is another scenarios where you will need to compare strings in TypeScript. When you required to check substrings and string content. I will show here two useful methods. ...
}// Works, since 'E' has a property named 'X' which is a number.f(E);// 编译期枚举enumLogLevel{ERROR,WARN,INFO,DEBUG}/** * This is equivalent to: * type LogLevelStrings = 'ERROR' | 'WARN' | 'INFO' | 'DEBUG'; */typeLogLevelStrings= keyoftypeofLogLevel;functionprintImportant...
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]; ...