Adding options to select with javascript

Question

I want this javascript to create options from 12 to 100 in a select with id=\"mainSelect\", because I do not want to create all of the option tags manually. Can you give me

Answer 1

The one thing I'd avoid is doing DOM operations in a loop to avoid repeated re-renderings of the page.

var firstSelect = document.getElementById('first select elements id'),
    secondSelect = document.getElementById('second select elements id'),
    optionsHTML = [],
    i = 12;

for (; i < 100; i += 1) {
  optionsHTML.push("Age" + i + "";
}

firstSelect.innerHTML = optionsHTML.join('\n');
secondSelect.innerHTML = optionsHTML.join('\n');

Edit: removed the function to show how you can just assign the html you've built up to another select element - thus avoiding the unnecessary looping by repeating the function call.