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
我希望这个问题仍然有意义。我使用这样的函数:
function enumKeys(target: Record<string, number|string>): string[] {
const allKeys: string[] = Object.keys(target);
const parsedKeys: string[] = [];
for (const key of allKeys) {
const needToIgnore: boolean
= target[target[key]]?.toString() === key && !isNaN(parseInt(key));
if (!needToIgnore) {
parsedKeys.push(key);
}
}
return parsedKeys;
}
function enumValues(target: Record<string, number|string>): Array<string|number> {
const keys: string[] = enumKeys(target);
const values: Array<string|number> = [];
for (const key of keys) {
values.push(target[key]);
}
return values;
}
例子:
enum HttpStatus {
OK,
INTERNAL_ERROR,
FORBIDDEN = 'FORBIDDEN',
NOT_FOUND = 404,
BAD_GATEWAY = 'bad-gateway'
}
console.log(enumKeys(HttpStatus));
// > ["OK", "INTERNAL_ERROR", "FORBIDDEN", "NOT_FOUND", "BAD_GATEWAY"]
console.log(enumValues(HttpStatus));
// > [0, 1, "FORBIDDEN", 404, "bad-gateway"]
其他回答
虽然答案已经提供了,但几乎没有人指向文档
下面是一个片段
enum Enum {
A
}
let nameOfA = Enum[Enum.A]; // "A"
请记住,string enum成员根本不会生成反向映射。
我看不正确的答案看累了,就自己做了。
这个有测试。 适用于所有类型的枚举。 正确地输入。
type EnumKeys<Enum> = Exclude<keyof Enum, number>
const enumObject = <Enum extends Record<string, number | string>>(e: Enum) => {
const copy = {...e} as { [K in EnumKeys<Enum>]: Enum[K] };
Object.values(e).forEach(value => typeof value === 'number' && delete copy[value]);
return copy;
};
const enumKeys = <Enum extends Record<string, number | string>>(e: Enum) => {
return Object.keys(enumObject(e)) as EnumKeys<Enum>[];
};
const enumValues = <Enum extends Record<string, number | string>>(e: Enum) => {
return [...new Set(Object.values(enumObject(e)))] as Enum[EnumKeys<Enum>][];
};
enum Test1 { A = "C", B = "D"}
enum Test2 { A, B }
enum Test3 { A = 0, B = "C" }
enum Test4 { A = "0", B = "C" }
enum Test5 { undefined = "A" }
enum Test6 { A = "undefined" }
enum Test7 { A, B = "A" }
enum Test8 { A = "A", B = "A" }
enum Test9 { A = "B", B = "A" }
console.log(enumObject(Test1)); // {A: "C", B: "D"}
console.log(enumObject(Test2)); // {A: 0, B: 1}
console.log(enumObject(Test3)); // {A: 0, B: "C"}
console.log(enumObject(Test4)); // {A: "0", B: "C"}
console.log(enumObject(Test5)); // {undefined: "A"}
console.log(enumObject(Test6)); // {A: "undefined"}
console.log(enumObject(Test7)); // {A: 0,B: "A"}
console.log(enumObject(Test8)); // {A: "A", B: "A"}
console.log(enumObject(Test9)); // {A: "B", B: "A"}
console.log(enumKeys(Test1)); // ["A", "B"]
console.log(enumKeys(Test2)); // ["A", "B"]
console.log(enumKeys(Test3)); // ["A", "B"]
console.log(enumKeys(Test4)); // ["A", "B"]
console.log(enumKeys(Test5)); // ["undefined"]
console.log(enumKeys(Test6)); // ["A"]
console.log(enumKeys(Test7)); // ["A", "B"]
console.log(enumKeys(Test8)); // ["A", "B"]
console.log(enumKeys(Test9)); // ["A", "B"]
console.log(enumValues(Test1)); // ["C", "D"]
console.log(enumValues(Test2)); // [0, 1]
console.log(enumValues(Test3)); // [0, "C"]
console.log(enumValues(Test4)); // ["0", "C"]
console.log(enumValues(Test5)); // ["A"]
console.log(enumValues(Test6)); // ["undefined"]
console.log(enumValues(Test7)); // [0, "A"]
console.log(enumValues(Test8)); // ["A"]
console.log(enumValues(Test9)); // ["B", "A"]
在线版本。
这不是你问题的确切答案,但它是解决你问题的一个技巧。
export module Gender {
export enum Type {
Female = 1,
Male = 2
};
export const List = Object.freeze([
Type[Type.Female] ,
Type[Type.Male]
]);
}
您可以以自己想要的方式扩展列表模型。
export const List = Object.freeze([
{ name: Type[Type.Female], value: Type.Female } ,
{ name: Type[Type.Male], value: Type.Male }
]);
现在,你可以这样使用它:
for(const gender of Gender.List){
console.log(gender.name);
console.log(gender.value);
}
or:
if(i === Gender.Type.Male){
console.log("I am a man.");
}
我写了一个helper函数来枚举一个枚举:
static getEnumValues<T extends number>(enumType: {}): T[] {
const values: T[] = [];
const keys = Object.keys(enumType);
for (const key of keys.slice(0, keys.length / 2)) {
values.push(<T>+key);
}
return values;
}
用法:
for (const enumValue of getEnumValues<myEnum>(myEnum)) {
// do the thing
}
该函数返回可以轻松枚举的内容,并将其转换为枚举类型。
我希望这个问题仍然有意义。我使用这样的函数:
function enumKeys(target: Record<string, number|string>): string[] {
const allKeys: string[] = Object.keys(target);
const parsedKeys: string[] = [];
for (const key of allKeys) {
const needToIgnore: boolean
= target[target[key]]?.toString() === key && !isNaN(parseInt(key));
if (!needToIgnore) {
parsedKeys.push(key);
}
}
return parsedKeys;
}
function enumValues(target: Record<string, number|string>): Array<string|number> {
const keys: string[] = enumKeys(target);
const values: Array<string|number> = [];
for (const key of keys) {
values.push(target[key]);
}
return values;
}
例子:
enum HttpStatus {
OK,
INTERNAL_ERROR,
FORBIDDEN = 'FORBIDDEN',
NOT_FOUND = 404,
BAD_GATEWAY = 'bad-gateway'
}
console.log(enumKeys(HttpStatus));
// > ["OK", "INTERNAL_ERROR", "FORBIDDEN", "NOT_FOUND", "BAD_GATEWAY"]
console.log(enumValues(HttpStatus));
// > [0, 1, "FORBIDDEN", 404, "bad-gateway"]