如何在 Javascript 集合 object 中的特定索引处添加元素？

Question

I tried using options.splice(index, 0, value); but it only works for arrays not for set objects. Don't suggest ES6 ways please.

Answer 1

You can convert the set to an array, do what you want and convert it back to a set.

// Assuming options is a Set
var optionsArray = Array.from(options);
optionsArray.splice(index, 0, value);
options = new Set(optionsArray);

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ES6 even though you don't want it:)

// Assuming options is a Set
const optionsArray = [...options];
optionsArray.splice(index, 0, value);
options = new Set(optionsArray);