我有一个这样定义的枚举:
export enum GoalProgressMeasurements {
Percentage = 1,
Numeric_Target = 2,
Completed_Tasks = 3,
Average_Milestone_Progress = 4,
Not_Measured = 5
}
然而，我希望它被表示为一个对象数组/列表从我们的API如下:
[{id: 1, name: 'Percentage'},
{id: 2, name: 'Numeric Target'},
{id: 3, name: 'Completed Tasks'},
{id: 4, name: 'Average Milestone Progress'},
{id: 5, name: 'Not Measured'}]
是否有简单和本地的方法来做到这一点，或者我必须构建一个函数，将枚举转换为int和字符串，并将对象构建为数组?
当前回答
我从几个月前就了解了typescript，下面的解决方案对我来说很有效。希望它也能帮助到一些人
export enum ScheduleType {
Basic = <any>'B',
Consolidated = <any>'C',
}
scheduleTypes = Object.keys(ScheduleType)
.filter((k, i) => i % 2)
.map((key: any) => {
return {
systemValue: key,
displayValue: ScheduleType[key],
};
});
它给出了如下的结果- [{displayValue: "Basic"， systemValue: "B"}， {displayValue: "Consolidated"， systemValue: "C"}]
其他回答
设enum变量为:
enum EnumName {
A = 1,
B = 2
};
那么列表是:
const list = Object.keys(Enum)
.filter((value => isNaN(Number(value)) === false))
.map(key => ({ id: key, value: Enum[key] }));
list的值为
list = [
{ id:1 , value: A },
{ id:2 , value: B },
];
有一个简单的解决方案，当你运行object。Keys (Enum)它会给你一个值和键的数组，在第一个slice Values中，在第二个slice key中，为什么我们不直接返回第二个slice，下面的代码对我来说是有用的。
enum Enum {
ONE,
TWO,
THREE,
FOUR,
FIVE,
SIX,
SEVEN
}
const keys = Object.keys(Enum);
console.log(keys.slice(keys.length / 2));
TS:
仅适用于短(<10个元素)enum
const keys = Object.keys(Enum).filter((el: string) => el.length > 1)
console.log(keys)
Object.keys()将返回一个包含['0'，'1'，'2'，'enumElement1'， 'enumElement2'， enumElement3']的数组 Filter()获取每个元素并检查其长度(因为字符串)，并从结果数组中排除所有数字
枚举是运行时存在的真实对象。所以你可以这样反向映射:
let value = GoalProgressMeasurements.Not_Measured;
console.log(GoalProgressMeasurements[value]);
// => Not_Measured
基于此，您可以使用以下代码:
export enum GoalProgressMeasurements {
Percentage = 1,
Numeric_Target = 2,
Completed_Tasks = 3,
Average_Milestone_Progress = 4,
Not_Measured = 5
}
let map: {id: number; name: string}[] = [];
for(var n in GoalProgressMeasurements) {
if (typeof GoalProgressMeasurements[n] === 'number') {
map.push({id: <any>GoalProgressMeasurements[n], name: n});
}
}
console.log(map);
参考:https://www.typescriptlang.org/docs/handbook/enums.html
另一种方法是使用ES8 Object.entries
export enum Weeks {
MONDAY = 1,
TUESDAY= 2,
WEDNESDAY = 3,
THURSDAY = 4,
FRIDAY = 5,
SATURDAY=6,
SUNDAY=7,
}
function convertEnumToArray(){
const arrayObjects = []
// Retrieve key and values using Object.entries() method.
for (const [propertyKey, propertyValue] of Object.entries(Weeks)) {
// Ignore keys that are not numbers
if (!Number.isNaN(Number(propertyKey))) {
continue;
}
// Add keys and values to array
arrayObjects.push({ id: propertyValue, name: propertyKey });
}
console.log(arrayObjects);
}
将产生以下内容:
[
{ id: 1, name: 'MONDAY' },
{ id: 2, name: 'TUESDAY' },
{ id: 3, name: 'WEDNESDAY' },
{ id: 4, name: 'THURSDAY' },
{ id: 5, name: 'FRIDAY' },
{ id: 6, name: 'SATURDAY' },
{ id: 7, name: 'SUNDAY' }
]
无耻地从这个博客偷来的
