How to parseInt a number that start with 0?

August 5, 2022

I have this string: '044600171940'.
I want to parse the string to a number with parseInt, but the value returns a number without the 0 in the front.

Is it possible to return the number with a leading 0 (e.g. 044600171940)?

var arr = ['044600171941','044600171940'];

var last = arr[arr.length -1];
var number = parseInt(last)
console.log(number)//44600171940

>Solution :

padStart(int, character) fills up the start of a string until the length is int characters long.

var arr = ['044600171941','044600171940'];

var last = arr[arr.length -1];

const addToNumberString = (intStr, value) => {
  let originalLength = intStr.length
  let sumInt = Number(intStr) + value;
  let sumIntStr = String(sumInt);

  return sumIntStr.padStart(originalLength, '0');
};

console.log(addToNumberString(last, 1)) // '044600171941'

…and here is a solution based off the fact that the value is always 12 characters long.

const numberLength = 12;

const addPadding = (number) => {
  return String(number).padStart(numberLength, 0);
};

var arr = ['044600171941','044600171940'];

var last = arr[arr.length -1];
var number = parseInt(last)

console.log( addPadding(17) )         // '000000000017'

console.log( addPadding(number) )     // '044600171940'

console.log( addPadding(number + 1) ) // '044600171941'