このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語):
string cannot be used as an index type
対処
関連リンク
Why I'm getting "Type 'String' cannot be used as an index type ...stackoverflow.com/.../why-im-getting-type-string-cann...
https://stackoverflow.com/questions/41709887/why-im-getting-type-string-cannot-be-used-as-an-index-t・・・
javascript - Typescript error - Type 'string[]' cannot be used as ...stackoverflow.com/.../typescript-error-type-string-cann...
https://stackoverflow.com/questions/50750764/typescript-error-type-string-cannot-be-used-as-an-index・・・
Typescript "Type String cannot be used as an index"fedidat.com/550-typescript-string-index/
https://fedidat.com/550-typescript-string-index/