jQuery函数

node.getSibings() 获取它的兄弟姐妹的元素
node.addClass() 添加某个类

window.jQuery = function(nodeOrSelector) {
let nodes = {
0: nodeOrSelector,
length: 1
}
nodes.addClass = function(classes) {}
nodes.text = function(text) {}
return nodes
}

var node2 = jQuery('ul > li')
{0: li, 1: li, length: 5, addClass: f, text: f}

node2.addClass(['blue'])
node2.text()
node2[0].classList.add('blue')