[Edit]

TypeScript - convert enum to array

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Created by:

Root-ssh

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In this article, we would like to show how to to get enum names or values in TypeScript.

Quick solution:

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enum Fruit {
    Apple,
    Orange,
    Cherry = 'cherry',
    Banana = 'banana'
}
​
const keys = Object.keys(Fruit);
​
const names = keys.filter(key => !/^[0-9]+$/.test(key));  // ['Apple', 'Orange', 'Cherry', 'Banana']
const values = names.map(key => Fruit[key as any]);       // [0, 1, 'cherry', 'banana']

Note: runnable example is available here.

Reusable code

Edit

The example contains reusable util that helps to extract data from the enums.

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class EnumUtils {
​
    private static REGEXP : RegExp = /^[0-9]+$/;
​
    public static getEntities<V extends string | number>(object: Record<string, string | number>, converter: (name: string) => V): Array<V> {
        const result = new Array<V>();
        for (let name in object) {
            if (!this.REGEXP.test(name)) {
                result.push(converter(name));
            }
        }
        return result;
    }
​
    public static getNames(object: Record<string, string | number>): Array<string> {
        return this.getEntities(object, name => name);
    }
​
    public static getValues(object: Record<string, string | number>): Array<string | number> {
        return this.getEntities(object, name => object[name]);
    }
}
​
​
// Usage example:
​
enum Fruit {
    Apple,
    Orange,
    Cherry = 'cherry',
    Banana = 'banana'
}
​
console.log(EnumUtils.getNames(Fruit));   // ['Apple', 'Orange', 'Cherry', 'Banana']
console.log(EnumUtils.getValues(Fruit));  // [0, 1, 'cherry', 'banana']

Note: runnable example is available here.

Output:

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['Apple', 'Orange', 'Cherry', 'Banana']
[0, 1, 'cherry', 'banana']

Warning: some tools may remove information about enums during source code optimization that makes impossible to extract enum names and values - e.g. preact-cli during production bundle building, browserify, etc.