export function formatValue(value: string | number): string | number {
  // Usa typeof para distinguir string de number

  if (typeof value === "string") {
    return value.toUpperCase();
  } else if (typeof value === "number") {
    return value * 2;
  }

  return value;
}

console.log(formatValue("hola")); 
console.log(formatValue(5));