converter/src/app/converter/hextodecconverter.ts

import {Converter} from './converter';

export class HexToDecConverter implements Converter {
  getDisplayname(): string {
    return 'Convert hexadecimal to decimal';
  }

  getId(): string {
    return 'hextodec';
  }

  convert(input: string): string {
    const n: number = parseInt(input, 16);
    if (isNaN(n)) {
      throw new Error('The input seems not to be a valid hexadecimal number.');
    }
    return n.toString(10);
  }
}