stringifying sets

In Javascript, Sets are Objects with a few special attributes. Notably, they’re iterable collections of unique elements.

One of the consequences of how Sets are constructed, however, is that they’re not stringify-able.¹

There are some simple solutions to this is to create an array before trying to stringify the elements.

For example:

const mySet = new Set([1,2,3,4,5,6,1]) // the duplicative 1 will be removed
console.log(JSON.stringify(mySet)) // “{}”
console.log(JSON.stringify([...mySet]) // “[1, 2, 3, 4, 5, 6]”

Footnotes

• ¹ javascript - JSON stringify a Set | Stack Overflow