尝试访问TypeScript词典时出现“不支持的索引器”

Question

I'm trying to make a Minecraft MakeCode extension in TypeScript and a dictionary is needed to map a string to a corresponding string:

const chars:{[index:string]:string} = {
  "A": "MSOJOQJ",
  "B": "JWIQWIQ"
  // ...
};

However when I try to look up a value of the dictionary:

let look = chars["A"];

TypeScript throws an error that it is unsupported indexer .

Setting the key-value pairs for the dictionary doesn't work either:

chars["C"] = "HIHWQHQ"; // unsupported indexer

Is there any fault in my code or is TypeScript bugged/too strict?

Answer 1

After further looking into the MakeCode environment, it appears that while it doesn't support dictionary indexers on mapped types, it does support dot access:

const dicto: { [key: string]: string } = {
    hello: "world",
    goodbye: "friends",
};

dicto["hello"] = "wow!"; // error
const b = dicto["goodbye"]; // error

dicto.hello = "wow!"; // ok
const c = dicto.goodbye; // ok, c inferred to be of type string