声明路由时出现常规'NodeJs/express'错误(类型错误：无法读取pathtoRegexp处未定义的属性“length”)

7gcisfzg 于 2023-03-17 发布在 Node.js

关注(0)|答案(5)|浏览(168)

I'm new at node.js , and this error cost me many efforts of investigations so I'm sharing this.
I've only tried to declare the express and some basic routers in my index.js:

const express = require('express');
const app = express();

app.get('/api/courses', (req, res)=>{
    res.send(courses);
});

app.get('/api/courses:id', (req, res)=>{
    const course = courses.find(c => c.id === parseInt(req.params.id));
    if (!course) res.send('The given id was not found...');
    res.send(course);   
});

app.get();

The error details:
\node_modules\path-to-regexp\index.js:63 path = ('^' + path + (strict ? '' : path[path.length - 1] === '/' ? '?' : '/?')) ^
TypeError: Cannot read property 'length' of undefined at pathtoRegexp (C:\Users...\node_modules\path-to-regexp\index.js:63:49) at new Layer (C:\Users...\node_modules\express\lib\router\layer.js:45:17) at Function.route (C:\Users...\node_modules\express\lib\router\index.js:494:15) at Function.app.(anonymous function) [as get] (C:\Users...\node_modules\express\lib\application.js:481:30) at Object. (C:...\index.js:24:5) at Module._compile (module.js:652:30) at Object.Module._extensions..js (module.js:663:10) at Module.load (module.js:565:32) at tryModuleLoad (module.js:505:12) at Function.Module._load (module.js:497:3)

node.js

来源：https://stackoverflow.com/questions/52132243/general-nodejs-express-error-when-declaring-routes-typeerror-cannot-read-pro

5条答案

按热度按时间

mwkjh3gx1#

该错误背后的原因是使用了不带param的app.get()方法，该方法需要端点url和回调作为参数。

赞(0）回复(0）举报 2023-03-17

iqih9akk2#

app.get();导致错误。
正如文档所述，app.get(path, callback [, callback ...])必须有一个路径参数（app.get(name)也必须有名称参数）。

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vpfxa7rd3#

我最近也遇到了这个问题，这是因为我的项目需要.env文件，其中定义了所有的基本路线，但不知何故，它被从项目中删除。因此，我发现这个问题是检查所有的配置/.env文件，您的node.js需要。

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9cbw7uwe4#

const express = require('express');
const app = express();

app.get('/api/courses', (req, res)=>{
    res.send(courses);
});

app.get('/api/courses:id', (req, res)=>{
    const course = courses.find(c => c.id === parseInt(req.params.id));
    if (!course) res.send('The given id was not found...');
    res.send(course);   
});

app.get(); // <= Remove this line of code and it will work. you need the path parameter in order for a app.get() to work

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r7knjye25#

可能检查app.get（）和app.post（）是否被留下任何边界尝试注解它并检查正如文档所述，app.get（path，callback [，callback ...]）必须有路径参数（app.get（name）也必须有名称参数）。

赞(0）回复(0）举报 2023-03-17