after looking at the document, I found that JavaScript Set has Add, but it doesn"t seem to be as good as Map as it does not have Get,. What are the useful scenarios for this Set? I had hoped to use Set to create Enum-like features, but it seemed hopeless.
Set is used to store unique value , the key point is unique, so there is .has method ( document ). As for .get , if you think about it, you will find that this semantics does not exist in Set, because Set is not a structure corresponding to keys and values.
the most typical scenario is the event listener:
so Set corresponds to an array, not an object.
< hr >if I want to simulate Enum, I don't understand why I use Set at first. Then realize that you may want to control the enumeration value only. Then you should use Symbol:
// enum.ts
const enum Color {
red,
green,
blue,
}
export default Color
// app.js
import Color from './enum.js';
const red = Color.red; // -> const red = 0 /* red */;but it also has the cost of learning, so it depends on whether you need it or not.
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