Large numbers multiplication

multiply.js

function mul(num1, num2) {

  // Convert to array of string in reverse order (right to left calc)
  num1 = `${num1}`.split('').reverse();
  num2 = `${num2}`.split('').reverse();
  
  // Init empty array
  const d = [];
  for(let i = 0; i < num1.length + num2.length; i++) {
    d[i] = 0;
  }
  
  // Calculate each digits
  for (let i = 0; i < num1.length; i++) {
    for (let j = 0; j < num2.length; j++) {
      d[i + j] += parseInt(num1[i]) * parseInt(num2[j]);
    }
  }
  
  const numbers = [];
  for(let i = 0; i < d.length; i++){
    const number = d[i] % 10;
    const carry = Math.floor(d[i] / 10);
    if (i + 1 < d.length){
      d[i + 1] += carry;
    }
    numbers.push(number);
  }

  return numbers.reverse().join('').replace(/^0*/, '');
}