Typescript object set type

Question

This reads the string and creates and array of objects which is used in various operations but when the final array is returned I need the year to be a number but at the moment it is a string

for (let i = 1; i < allFileLines.length; i++) {
                    const data = allFileLines[i].split("|");
                    if (data.length === newheaders.length) {
                        const tarry: Icface = {
                            title: null as string,
                            id: null as string,
                            year: null as number,
                        };
                        for (let j = 0; j < newheaders.length; j++) {
                            tarry[newheaders[j]] = data[j];
                        }
                        if (typeof tarry[2] === "number") {
                            Log.trace("number");
                        }
                        // tslint:disable-next-line:no-console
                        // console.log(lines);
                        // Log.trace(JSON.parse(JSON.stringify(tarry)));
                        lines.push(tarry);
                    }
                }

and interface is

export interface Icface {
    title: string;
    id: string;
    year: number;
    [key: string]: string | number;
}

So after the processing the year is being returned as "2018" but it needs to be 2018. Kind of baffling that I am able to operate on the string year with < and ===. Any ideas?

Answer 1

You have split a string into an array of strings, try

const tarry: Icface = {
  title: data[0],
  id: data[1],
  year: parseInt(data[2]),
};

Answer 2

The interface Icface below allows the property year be string or number

export interface Icface {
  title: string;
  id: string;
  year: number;
 [key: string]: string | number; // it allows ['year'] be string or number
}

Please try changing the for loop of for (let j = 0; j < newheaders.length; j++) as

for (let j = 0; j < newheaders.length; j++) {
  if (newheaders[j] === 'year') {
    tarry.year = +data[j];
  else {
    tarry[newheaders[j]] = data[j];
  }
}