Does Node run all the code inside required modules?

Question

Are node modules run when they are required?

For example: You have a file foo.js that contains some code and some exports.

When I import the file by running the

Answer 1

Some examples..

'use strict';
var a = 2 * 4;  //this is executed when require called
console.log('required'); //so is this..    
function doSomething() {};  //this is just parsed
module.exports = doSomething;  //this is placed on the exports, but still not executed..