process.env.PORT 未定义。 typescript出现的问题

Question

I am new to typescript.

Imported and used dotenv package but still getting undefined It is necessary to declare interface for the dotenv variables?

import express,{Application} from 'express';
import bodyParser from 'body-parser';
import  dotenv from 'dotenv';
dotenv.config();

const app : Application = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

console.log(process.env.PORT);   //undefined

app.listen(3000, ()=>console.log(`server started on 

http://localhost:${3000}`));

.env File

PORT = 3000
SECRET=SOME_SECRET

package.json

{
  "dependencies": {
    "body-parser": "^1.20.1",
    "dotenv": "^16.0.3",
    "express": "^4.18.2",
    "express-session": "^1.17.3",
    "nodemon": "^2.0.20",
    "ts-node": "^10.9.1",
    "typescript": "^4.9.4"
  },
}

Answer 1

You don't have to declare interfaces for environment variables in Typescript. Where's your.env file located relative to the Typescript file you pasted?

The.env file should be at the project's root, in the same directory as the project's package.json file. If it's located somewhere that's not the root or that dotenv can't figure out, I'd recommend using the following example for configuring dotenv:

dotenv.config( { path: '../relative/path/.env' });