javascript - NodeJS behavior of exporting class object

Question

I am trying to understand the behavior of exporting class object instead of class name. Please help me make understand. Example

class Util {
  method() {
    return "method";
  }
}

module.exports = new Util();

and then importing it like

import Util from 'Util';

question from:https://stackoverflow.com/questions/65887632/nodejs-behavior-of-exporting-class-object

Answer 1

I want to understand, how many times the object will be created?

Once, in the normal case. Modules are loaded and cached, and if they're imported by multiple other modules, those modules all see the same instance of the module doing the exporting.

When using CJS modules, the cache is require.cache and you can clear a module from the cache by deleting the property for it from the require.cache object, meaning that it will get loaded fresh the next time it's require'd. (I don't think it's possible to do that with ESM modules.)

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Note: You're mixing CJS (module.exports =...) and ESM (import). I suggest you pick one and use it consistently, not least because you can't use require to import an ESM module.