In Node.js, how do I “include” functions from my other files?

Question

Let\'s say I have a file called app.js. Pretty simple:

var express = require(\'express\');
var app = express.createServer();
app.set(\'views\', __dirname + \         


        

Answer 1

I just want to add, in case you need just certain functions imported from your tools.js, then you can use a destructuring assignment which is supported in node.js since version 6.4 - see node.green.

---

Example: (both files are in the same folder)

tools.js

module.exports = {
    sum: function(a,b) {
        return a + b;
    },
    isEven: function(a) {
        return a % 2 == 0;
    }
};

main.js

const { isEven } = require('./tools.js');

console.log(isEven(10));

output: true

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This also avoids that you assign those functions as properties of another object as its the case in the following (common) assignment:

const tools = require('./tools.js');

where you need to call tools.isEven(10).

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NOTE:

Don't forget to prefix your file name with the correct path - even if both files are in the same folder, you need to prefix with ./

From Node.js docs:

Without a leading '/', './', or '../' to indicate a file, the module must either be a core module or is loaded from a node_modules folder.