JavaScript Singleton Pattern

javscript_singelton.js

let logger_instance = null;
class Logger {
    constructor() {
    }
 
    static instance(message, user, serviceError, note, code){
      console.log('static instance called');
      if(logger_instance === null){
        	console.log('==== create');
          logger_instance = new Logger();
      }
      console.log('instance', logger_instance);
      console.log('type', typeof logger_instance);
      return logger_instance
    }

  }


var log = Logger.instance();
var _log = Logger.instance();