使用require时如何找到.js文件的正确路径

Question

I have an ExpressJS project where I want to use .js module inside another. I use require to get the .js module but it can't find the module because the path is not correct. How can I see or find what is the correct path for a local module.

Here is my project hierarchy/structure

This is what I have tried inside programController.js - another thing is I don't quite understand using "." in path string.

var Program = require('.././program.js');
var FinishProgram = require('.././finishProgram');

Answer 1

The . and .. notation in paths represent a path relative to the file they're being required from.

Meaning of . and .. Wildcards

. - inside the same directory this file is in (also referred to as the current working directory)

.. - inside the parent directory of the current directory

When you use multiples of these together it creates a relative path pattern. So for programController.js to access program.js your path should be

var Program = require('../../models/program');

This path means, go up 2 folders to the App directory and locate the models folder, then load the file program.js .

Following the same rules, you can also access finishProgram.js

var FinishProgram = require('../../models/finishProgram');

Answer 2

. represents the current directory and is redundant in your case.

The paths are simple relative paths that are used to determine how to navigate to the required files.

This should work for you:

var Program = require('../../models/program');
var FinishProgram = require('../../models/finishProgram');

Note that the extension .js is not required.