js .before code example

Example 1: javascript add div before element

var my_elem = document.getElementById('my_id');

var span = document.createElement('span');
    span.innerHTML = '*';
    span.className = 'asterisk';

my_elem.parentNode.insertBefore(span, my_elem);

Example 2: how to add css for ::before event in jquery

how to add css for ::before event in jquery