Digits of a number when iterating through a loop in JavaScript

Suppose that when iterating over numbers, we want to get some digit from these numbers. For example, we want to make a number be displayed on the console if its first digit is 1 or 2.

I remind you that you can’t refer to the characters of a number directly, that is, it won’t work like this:

javascriptfor (let i = 1; i <= 100; i++) {
  if (i[0] == 1 || i[0] == 2) { // that won't work
    console.log(i);
  }
}

First you need to convert the number to a string and then get a certain character of the returned string, like this:

javascriptfor (let i = 1; i <= 100; i++) {
  let str = String(i); // converting number to string
  
  if (str[0] === '1' || str[0] === '2') {
    console.log(i);
  }
}