In Typescript I get a string variable that contains the name of my defined enum.
How can I now get all values of this enum?
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you could use reflection, something like this post stackoverflow.com/questions/15338610/…. Anyway I would first think if that is the right way to go or you can access it in a "normal" wayiberbeu– iberbeu2016-08-02 11:50:56 +00:00Commented Aug 2, 2016 at 11:50
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2 Answers
Typescript enum:
enum MyEnum {
First, Second
}
is transpiled to JavaScript object:
var MyEnum;
(function (MyEnum) {
MyEnum[MyEnum["First"] = 0] = "First";
MyEnum[MyEnum["Second"] = 1] = "Second";
})(MyEnum || (MyEnum = {}));
You can get enum instance from window["EnumName"]:
const MyEnumInstance = window["MyEnum"];
Next you can get enum member values with:
const enumMemberValues: number[] = Object.keys(MyEnumInstance)
.map((k: any) => MyEnumInstance[k])
.filter((v: any) => typeof v === 'number').map(Number);
And enum member names with:
const enumMemberNames: string[] = Object.keys(MyEnumInstance)
.map((k: any) => MyEnumInstance[k])
.filter((v: any) => typeof v === 'string');
See also How to programmatically enumerate an enum type in Typescript 0.9.5?
2 Comments
Jochen Kühner
Window[enumname] did not work, maybe because we use namespaces. But "eval(enumname)" did work.
Dhanraj Acharya
Is there a React friendly alternative to this?
As an alternative to the window approach that the other answers offer, you could do the following:
enum SomeEnum { A, B }
let enumValues:Array<string>= [];
for(let value in SomeEnum) {
if(typeof SomeEnum[value] === 'number') {
enumValues.push(value);
}
}
enumValues.forEach(v=> console.log(v))
//A
//B
1 Comment
Dhanraj Acharya
If we had the instance of the enum then it is easy to get the list of values. The questions was how do we get the enum instance from the string value.