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...
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...
TypeScript - Strings TypeScript - Boolean TypeScript - Arrays TypeScript - Tuples TypeScript - Enums TypeScript - Any TypeScript - Never TypeScript - Union TypeScript - Literal Types TypeScript - Symbols TypeScript - null vs. undefined TypeScript - Type Aliases TypeScript Control Flow TypeSc...
Enums and Strings Before we look further into enums let's look at the JavaScript that it generates, here is a sample TypeScript: AI检测代码解析 enumTristate{False,True,Unknown} 1. 2. 3. 4. 5. generates the following JavaScript:
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 ...
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. ...
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 ...
}// 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...