Is it possible to get the values of an enum in TypeScript as an array?
Like this:
enum MyEnum {
FOO = 'foo',
BAR = 'bar'
}
becomes
['foo', 'bar']
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5 Answers
Yes, it is possible to use:
Object.values(MyEnum)
because enum is an JS object after compilation:
var MyEnum;
(function (MyEnum) {
MyEnum["FOO"] = "foo";
MyEnum["BAR"] = "bar";
})(MyEnum || (MyEnum = {}));
1 Comment
ZiiMakc
This answer is not correct for number enums
For a fully typed code, you may want to infer the list of values as a type with some help of the template literal operator:
enum MyEnum {
FOO = 'foo',
BAR = 'bar'
}
type MyEnumValue = `${MyEnum}`
// => type MyEnumValue = "foo" | "bar"
const values: MyEnumValue[] = Object.values(MyEnum)
// => ["foo", "bar"]
Reference article: Get the values of an enum dynamically (disclaimer: author here)
1 Comment
ZiiMakc
This answer is not correct for number enums
The simplest way to do it for a string enum is to use Object.values
enum MyEnum {
FOO = 'foo',
BAR = 'bar'
}
console.log(Object.values(MyEnum));
answered May 8, 2019 at 8:26
Titian Cernicova-Dragomir
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1 Comment
patelarpan
this answer is in more detail stackoverflow.com/questions/39372804/…
Imho @Fyodor's solution is cleaner because it covers string enums:
const enumAsArray = Object.values(MyEnum).filter(value => typeof value === 'string')
3 Comments
Fyodor
Or
const enumAsArray = Object.values(MyEnum).filter(value => typeof value === 'string') (replace 'string' with necessary type) To remove indexes I mean
Marco Nascimento
Also a nice approach :)
Andrii M4n0w4R
This looks weird.. Why cut half of values? What if we have odd length? Splice is definitely not needed.
This function should work with numeric enums as well and it type-checks:
type EnumObject = {[key: string]: number | string};
type EnumObjectEnum<E extends EnumObject> = E extends {[key: string]: infer ET | string} ? ET : never;
function getEnumValues<E extends EnumObject>(enumObject: E): EnumObjectEnum<E>[] {
return Object.keys(enumObject)
.filter(key => Number.isNaN(Number(key)))
.map(key => enumObject[key] as EnumObjectEnum<E>);
}
For example:
enum NumEnum {
A,
B,
C,
}
// The type is inferred as NumEnum[]
let numEnumValues = getEnumValues(NumEnum);
I've posted more details here: How to get an array of enum values in TypeScript
1 Comment
ZiiMakc
This will not work for ` enum X { "012" = 1 } `