How can I get the browser's scrollbar sizes?

Question

How can I determine the height of a horizontal scrollbar, or the width of a vertical one, in JavaScript?

Answer 1

This life-hack decision will give you opportunity to find browser scrollY width (vanilla JavaScript). Using this example you can get scrollY width on any element including those elements that shouldn't have to have scroll according to your current design conception,:

getComputedScrollYWidth     (el)  {

  let displayCSSValue  ; // CSS value
  let overflowYCSSValue; // CSS value

  // SAVE current original STYLES values
  {
    displayCSSValue   = el.style.display;
    overflowYCSSValue = el.style.overflowY;
  }

  // SET TEMPORALLY styles values
  {
    el.style.display   = 'block';
    el.style.overflowY = 'scroll';
  }

  // SAVE SCROLL WIDTH of the current browser.
  const scrollWidth = el.offsetWidth - el.clientWidth;

  // REPLACE temporally STYLES values by original
  {
    el.style.display   = displayCSSValue;
    el.style.overflowY = overflowYCSSValue;
  }

  return scrollWidth;
}