Javascript 'require()' method

Question

In python, when you import a module the statements inside the 'if name == main' block of the imported module is not executed.

Is there any equivalent approach which can prevents the execution of unwanted statements in the imported module in javascript?

• fuyushimoya: Accessing the main module#, you mean this?

Answer 1

Via fuyushimoya's comment.

When a file is run directly from Node, require.main is set to its module. That means that you can determine whether a file has been run directly by testing

require.main === module

For a file foo.js, this will be true if run via node foo.js, but false if run by require('./foo').

— Node.js documentation

So:

if (require.main === module) {
 // Code that runs only if the module is executed directly
} else {
 // Code that runs only if the code is loaded as a module
}

• fuyushimoya: I'm not sure his condition though, as I'm still learning python, if in python this way is to create a master-slave structure, then maybe cluster with cluster.isMaster is what he wants?
• Shinto C V: @fuyushimoya .. in python it is .. if __name__ == '__main__': //code thank you :)
• ivoszz: In addition to this answer, common pattern to include some statements in module which will not be executed when module is required is: if (!module.parent) { // not executed with require } else { // executed only with require }

Answer 2

Simply group your statements inside functions, and export the functions you want.

exports.function1 = new function () {
 //some code
}
function function2() {
 //some other code 
}

More on it here.

• Quentin: You seem to have completely misunderstood the question.