源代码如下： 首先是index的

var express = require('express') var app = express()

var on = '0'

app.get('/get',function(req,res){ var data = { 'on':on } console.log(data) res.json(data) })

app.get('/set',function(req,res){ if(req.query.mon =="0" || req.query.mon == "1") on = req.query.mon var data = { 'on':on } console.log(data) res.json(data) })

//利用ejs模版显示web浏览器界面 app.set('view engine','ejs') app.get('/',function(req,res){ var state = "开" if(on == "0") state = "关" res.render("default",{lightState:state}) })

var server = app.listen(8000,function(){ var host = server.address().address; var port = server.address().port; console.log("addres:%s, port:%s",host,port) })

default的源代码：

当前灯的状态:

用一个json对象保存灯的状态就行了，方便扩展，然后html传递对应的id进行状态控制。帮助到你能点个采纳吗，谢谢~

index.js

var express = require('express');
var app = express();
//灯状态，更多给json对象添加不同的键
var lightState = { light1: '关', light2: '关' }

app.get('/get', function (req, res) {
    var data = { 'on': lightState[req.query.attr] };
    console.log(data)
    res.json(data);
});

app.get('/set', function (req, res) {
    lightState[req.query.attr] = req.query.mon;
    var data = { on: lightState[req.query.attr] }
    console.log(data)
    res.json(data)
});

app.set('view engine', 'ejs')
app.get('/', function (req, res) {
    res.render('default', lightState)
});

var server = app.listen(8000, function () {
    var host = server.address().address;
    var port = server.address().port;
    console.log('addres:%s, port:%s',host,port)
})

default.ejs

<script src="https://g.csdnimg.cn/??lib/jquery/1.12.4/jquery.min.js"></script>
<script type="text/javascript">
    function changeState(state, id) {
        $.get('/set?mon=' + state+'&attr='+id, function (data, status) {
             $('#' + id).text(data.on);console.log(data)
        });
    }
</script>
<h2>当前等状态</h2>
<h1 style="color:#f00" id="light1"><%=light1%></h1>
<button onclick="changeState('开','light1')">开灯</button>
<button onclick="changeState('关','light1')">关灯</button>
<h1 style="color:#f00" id="light2"><%=light2%></h1>
<button onclick="changeState('开','light2')">开灯</button>
<button onclick="changeState('关','light2')">关灯</button>
<div style="height:300px"></div>