How ot fix funciton according TS?

September 15, 2022

Here is a funciton:

function factoryTableView(category: number) {
    const views =  {
      1: new ImportExportTable()
    };

        return views[category];
}

I got this error message:

Element implicitly has an 'any' type because expression of type 'number' can't be used to index type '{ 1: ImportExportTable; }'.
  No index signature with a parameter of type 'number' was found on type '{ 1: ImportExportTable; }'.

How to fix it?

>Solution :

Objects implicitly have strings for their properties unless you specify otherwise.

Explicitly define a type for views if you want to use numbers for the property names.

function factoryTableView(category: number) {
    const views: Record<number, ImportExportTable> = {
        1: new ImportExportTable()
    };
    return views[category];
}

(They will still be strings in JS, but TypeScript will require that you use numbers to access them and they will be converted to strings only at runtime).