js实现jq的parents方法（）

function getParents(el, parentSelector /* optional */) {
                console.log(el);
                // If no parentSelector defined will bubble up all the way to *document*
                if (parentSelector === undefined) {
                    parentSelector = document;
                }

                var parents = [];
                var p = el.parentNode;

                while (p !== parentSelector) {
                    
                    var o = p;
                    parents.push(o);
                    p = o.parentNode;
                }
                parents.push(parentSelector); // Push that parentSelector you wanted to stop at
                console.log(parents);
                return parents;
            }
            getParents(document.getElementById('ResTableList'), document.getElementById('main')); 

会把你传的第一个参数的那个元素一直往上找，直到第二个参数的那个元素，取return的parents的最后一位