Question

var express = require('express');
var app = express();
app.get('/products/productList/:id', (res, req) => {
   console.log("product Id - " + req.params.id);
});

此代码有什么问题？我该怎么做才能避免以下错误

TypeError: Cannot read property 'id' of undefined
at app.get (E:\Projects\Craiglist\trial\app.js:46:46)
at Layer.handle [as handle_request] (E:\Projects\Craiglist\trial\node_modules\express\lib\router\layer.js:95:5)
at next (E:\Projects\Craiglist\trial\node_modules\express\lib\router\route.js:137:13)
at Route.dispatch (E:\Projects\Craiglist\trial\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (E:\Projects\Craiglist\trial\node_modules\express\lib\router\layer.js:95:5)
at E:\Projects\Craiglist\trial\node_modules\express\lib\router\index.js:281:22
at param (E:\Projects\Craiglist\trial\node_modules\express\lib\router\index.js:354:14)
at param (E:\Projects\Craiglist\trial\node_modules\express\lib\router\index.js:365:14)
at Function.process_params (E:\Projects\Craiglist\trial\node_modules\express\lib\router\index.js:410:3)
at next (E:\Projects\Craiglist\trial\node_modules\express\lib\router\index.js:275:10)

Answer 1

(res, req)

你改变了函数参数的顺序：）

请求是第一个参数，响应是第二个。

试试这个：

app.get('/products/productList/:id', (req, res) => {
   console.log("product Id - " + req.params.id);
});

Answer 2

确保您required body-parser。并使用bodyParser.urlencoded。

var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: false }));

这应该在您的.get路线定义之前。

你必须在<{p>}之前做npm install body-parser

Nodejs Api参数传递和控制台记录参数

2 个答案: