基本的node.js中间件

Question

此代码返回＆＃34; var2未定义＆＃34;，如何在router.get（＆＃39; /＆＃39;）句子中使用var2？

提前致谢

    `//router

    var express = require('express');
    var router = express.Router();

    router.use('/', function(req, res, next){
        var2: "That is a var 2";
        next();
    });

    router.get('/', function(req, res, next){
        res.send(var2);
    });

    module.exports = router;`

Answer 1

以下是如何;

var express = require('express');
        var router = express.Router();
        var var2='';
        router.use('/', function(req, res, next){
            var2 = "That is a var 2";
            next();
        });

        router.get('/', function(req, res, next){
            res.send(var2);
        });

        module.exports = router;