我想迭代一个TypeScript枚举对象,并获得每个枚举符号名称,例如: enum myEnum {entry1, entry2}
for (var entry in myEnum) {
// use entry's name here, e.g., "entry1"
}
我想迭代一个TypeScript枚举对象,并获得每个枚举符号名称,例如: enum myEnum {entry1, entry2}
for (var entry in myEnum) {
// use entry's name here, e.g., "entry1"
}
当前回答
这里发现的另一个有趣的解决方案是使用ES6 Map:
export enum Type {
low,
mid,
high
}
export const TypeLabel = new Map<number, string>([
[Type.low, 'Low Season'],
[Type.mid, 'Mid Season'],
[Type.high, 'High Season']
]);
USE
console.log(TypeLabel.get(Type.low)); // Low Season
TypeLabel.forEach((label, value) => {
console.log(label, value);
});
// Low Season 0
// Mid Season 1
// High Season 2
其他回答
基于上面的一些回答,我提出了这个类型安全的函数签名:
export function getStringValuesFromEnum<T>(myEnum: T): (keyof T)[] {
return Object.keys(myEnum).filter(k => typeof (myEnum as any)[k] === 'number') as any;
}
用法:
enum myEnum { entry1, entry2 };
const stringVals = getStringValuesFromEnum(myEnum);
stringVals的类型是'entry1' | 'entry2'
看看它的实际应用
Typescript游乐场示例
enum TransactionStatus {
SUBMITTED = 'submitted',
APPROVED = 'approved',
PAID = 'paid',
CANCELLED = 'cancelled',
DECLINED = 'declined',
PROCESSING = 'processing',
}
let set1 = Object.entries(TransactionStatus).filter(([,value]) => value === TransactionStatus.SUBMITTED || value === TransactionStatus.CANCELLED).map(([key,]) => {
return key
})
let set2 = Object.entries(TransactionStatus).filter(([,value]) => value === TransactionStatus.PAID || value === TransactionStatus.APPROVED).map(([key,]) => {
return key
})
let allKeys = Object.keys(TransactionStatus)
console.log({set1,set2,allKeys})
你可以这样做,我认为这是最短、最干净、最快的:
Object.entries(test).filter(([key]) => (!~~key && key !== "0"))
给定以下混合类型枚举定义:
enum testEnum {
Critical = "critical",
Major = 3,
Normal = "2",
Minor = "minor",
Info = "info",
Debug = 0
};
它将会变成以下内容:
var testEnum = { 关键:“至关重要的”, 主要:3, 正常:“2”, 小:“小”, 信息:“信息”, 调试:0, [0]:“关键”, [1]: 3, [2]:“2”, [3]:“小”, [4]:“信息”, [5]: 0 } 函数safeEnumEntries(test) { return Object.entries(test).filter(([key]) => (!~~key && key !== "0"); }; console.log (safeEnumEntries (testEnum));
执行函数后,你只会得到好的条目:
[
["Critical", "critical"],
["Major", 3],
["Normal", "2"],
["Minor", "minor"],
["Info", "info"],
["Debug", 0]
]
这里发现的另一个有趣的解决方案是使用ES6 Map:
export enum Type {
low,
mid,
high
}
export const TypeLabel = new Map<number, string>([
[Type.low, 'Low Season'],
[Type.mid, 'Mid Season'],
[Type.high, 'High Season']
]);
USE
console.log(TypeLabel.get(Type.low)); // Low Season
TypeLabel.forEach((label, value) => {
console.log(label, value);
});
// Low Season 0
// Mid Season 1
// High Season 2
我通过搜索“TypeScript iterate over enum keys”找到了这个问题。所以我只想给出对我来说有用的解。也许对别人也有帮助。
我的情况如下:我想在每个枚举键上迭代,然后过滤一些键,然后访问一些对象,其中键作为枚举的计算值。这就是没有TS误差的方法。
enum MyEnum = { ONE = 'ONE', TWO = 'TWO' }
const LABELS = {
[MyEnum.ONE]: 'Label one',
[MyEnum.TWO]: 'Label two'
}
// to declare type is important - otherwise TS complains on LABELS[type]
// also, if replace Object.values with Object.keys -
// - TS blames wrong types here: "string[] is not assignable to MyEnum[]"
const allKeys: Array<MyEnum> = Object.values(MyEnum)
const allowedKeys = allKeys.filter(
(type) => type !== MyEnum.ONE
)
const allowedLabels = allowedKeys.map((type) => ({
label: LABELS[type]
}))