dom操作相关，byebye T T

o = {
    name: 'aa',
    price: 11,
}function add(items) {
    var bodys = document.getElementsByTagName('tbody');
    var trs = document.getElementsByTagName('tr');
    var trLen = trs.length;
    var str = `
        <td>${items['name']}</td>
        <td>${items['price']}</td>
        <td><a href="javascript:void(0);">删除</a></td>`        var tr2 = document.createElement("tr");
        tr2.innerHTML = str;
        bodys[bodys.length - 1].appendChild(tr2);        var sum = 0;
        for (var i = 1; i < trs.length - 1; i++) {
            var tds = trs[i].getElementsByTagName('td');
            // print(tds[1].innerText)
            sum +=  parseFloat(tds[1].innerText)
        }        var foot = document.getElementsByTagName('tfoot')[0];
        var all = foot.getElementsByTagName('td')[0].innerText;
        var rows = trs.length;
        var result = `${sum.toFixed(2)}(${rows - 2}件商品)`;
        foot.getElementsByTagName('td')[0].innerText = result;}function bind() {
    var bodys = document.getElementById("jsTrolley");
    var trs = bodys.getElementsByTagName("tr");    //给tr绑定click事件
    for(var i in trs){
      trs[i].onclick = function(e) {
        trs[this.rowIndex].parentNode.removeChild(trs[this.rowIndex]);
        var sum = 0;
        for (var i = 1; i < trs.length - 1; i++) {
            var tds = trs[i].getElementsByTagName('td');
            // print(tds[1].innerText)
            sum +=  parseFloat(tds[1].innerText)
        }        var foot = document.getElementsByTagName('tfoot')[0];
        var all = foot.getElementsByTagName('td')[0].innerText;
        var rows = trs.length;
        var result = `${sum.toFixed(2)}(${rows - 2}件商品)`
        // print(result)
        foot.getElementsByTagName('td')[0].innerText = result;
      };
    }}