Accessing prototype method or function undefined

Question

I'm learning to work with prototype but have some problems in exporting and using it in other files. The require part works but I can't access to the properties or methods in my data.js.

If i want use myFunction I'm getting myFunction is not a function and for properties undefined

I also don't understand why function(){}; instead of let Data = {}; works...

// data.js
let Data = function(){}; 

Data.prototype.integers = [0,1,3,2,8,4,11,22,74,98,111,5];

Data.prototype.myFunction= function (text){
  return text
}
module.exports.Data  = Data;


// main.js
let Numbers = require ("./data.js");
console.log(Numbers.myFunction("some text"), Numbers.integers ); // myFunction is not a function

Answer 1

It's because you're adding members to Data.prototype.

Change module.exports.Data = Data with module.exports.Data = new Data().

Some advise

Unless you want to do stuff with object-oriented programming, I would refactor your code as follows:

// data.js
module.exports.Data = {
   integers: [0,1,3,2,8,4,11,22,74,98,111,5],

   myFunction: function (text){
        return text
   }
}

So you're code in main.js will work as well.