How to find the highest z-index using jQuery

Question

I have a number of div elements with different z-index. And I want to find the highest z-index among these divs - how can I achieve it?

CSS:

#layer-1         


        

Answer 1

Vanilla JS, not 100% cross-browser. Including as reference for future readers/alternative method.

function getHighIndex (selector) {
    // No granularity by default; look at everything
    if (!selector) { selector = '*' };

    var elements = document.querySelectorAll(selector) ||
                   oXmlDom.documentElement.selectNodes(selector),
        i = 0,
        e, s,
        max = elements.length,
        found = [];

    for (; i < max; i += 1) {
        e = window.getComputedStyle(elements[i], null).zIndex || elements[i].currentStyle.zIndex;
        s = window.getComputedStyle(elements[i], null).position || elements[i].currentStyle.position;

        // Statically positioned elements are not affected by zIndex
        if (e && s !== "static") {
          found.push(parseInt(e, 10));
        }
    }

    return found.length ? Math.max.apply(null, found) : 0;
}