Typescript loop through a Set of values

Question

I have the following weird issue on my code using Typescript 2.6. I 'm trying to loop through a Set of string values but I get the following error and I don't understand why.

'Type 'Set' is not an array type or a string type. '

Here is what I have:

loopThroughSet(): void {

        let fruitSet = new Set()
        .add('APPLE')
        .add('ORANGE')
        .add('MANGO');

        for (let fruit of fruitSet) {
            console.log(fruit);
        }
}

Does anyone knows what's the problem? Thanks in advance

possible duplicate of https://stackoverflow.com/questions/35193471/how-to-iterate-over-a-set-in-typescript — Safiyya, Feb 20 '18 at 13:35
Possible duplicate of [How to iterate over a Set in TypeScript?](https://stackoverflow.com/questions/35193471/how-to-iterate-over-a-set-in-typescript) — Ele, Feb 20 '18 at 13:43

score 4 · Accepted Answer · answered Feb 20 '18 at 13:41

4

Set are not define in TS, you need to configure TS with es2017.object or convert Set values to array :

for (var item of Array.from(fruitSet.values())) {
  console.log(item);
}

answered Feb 20 '18 at 13:41

Léo R.

2,620
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Thanks Leo...that works.Thanks all of the responses. – Bad_Pan Feb 20 '18 at 13:50

score 2 · Answer 2 · answered Feb 20 '18 at 13:41

2

You can use fruitSet.forEach( fruit => ... )

If you want to use for..of, try spread operator: for (const fruit of [...fruitsSet]) { ... }

answered Feb 20 '18 at 13:41

Mixalloff

827
4
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score 0 · Answer 3 · answered Feb 02 '21 at 14:21

In my case, I needed to iterate through a range of seven items without defining and using a variable that would be marked as unused by ESLint, and the spread syntax helped a lot.

[...Array(7)].map(() => {
    // some code
});

instead of

for (const _ of range(0, 7)) {
    // Some code
}

Typescript loop through a Set of values

3 Answers3