How to loop through TypeScript enum?

Question

I have next enum:

export enum Suite {
  Spade = '♠',
  Heart = '♥',
  Club = '♣',
  Diamond = '♦',
}

Trying to implement loop, but getting error

  for (let suite in Suite) {
    console.log('item:', Suite[suite]);
  }

Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'typeof Suite'. No index signature with a parameter of type 'string' was found on type 'typeof Suite'.ts(7053)

How can I fix that?

Answer 1

You need to narrow the type of your suite key with a type constraint. You can do this by declaring it before the loop:

enum Suite {
  Spade = '♠',
  Heart = '♥',
  Club = '♣',
  Diamond = '♦',
}

let suite: keyof typeof Suite;
for (suite in Suite) {
    const value = Suite[suite];
    // ...
}

Or use Object.entries:

for (const [key, value] of Object.entries(Suite)) {
    // key = Spade, etc.
    // value = ♠, etc.
}

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