function findElement(arr, predicate) {
  for (const [index] of arr.entries()) {
    const value = arr[index];
    if (predicate(value)) {
      return { value, index };
    }
  }
  return { value: undefined, index: -1 };
}

const arreglo = [7, 1, 2];
const { value, index } = findElement(arreglo, x => x % 2 !== 0);
console.log(index, value);