MERN Stack New Batch

  const events = require ( 'events' ) ; const e = new events .EventEmitter() ; e. setMaxListeners ( 3 ) ; //=========== e. on ( 'event1' ,function (name , message) { console . log ( 'event1' ) ; console . log ( ` ${name} ${message} ` ) ; }) e. emit ( 'event1' , 'nayan' , 'Hello' ) ;

const events = require ( 'events' ) ; const e = new events .EventEmitter() ; e. setMaxListeners ( 3 ) ; //=========== e. on ( 'event1' ,function (name , message) { console . log ( 'event1' ) ; console . log ( ` ${name} ${message} ` ) ; }) e. emit ( 'event1' , 'nayan' , 'Hello' ) ;

  const events = require ( 'events' ) ; const e = new events .EventEmitter() ; e. setMaxListeners ( 4 ) ; //===========Example1 e. on ( 'event1' ,function () { console . log ( 'event1' ) ; }) e. on ( 'event1' ,function () { console . log ( 'event2' ) ; }) e. on ( 'event1' ,function () { console . log ( 'event3' ) ; }) e. on ( 'event1' ,function () { console . log ( 'event4' ) ; }) //==============call //e.emit('event1'); //i want output Like //event1 //event3 let a=e. listeners ( 'event1' ) ; a. forEach ((item , index)=>{ if (index === 0 || index === 2 ) { item() ; // 👉 This actually CALLS the function } })

  const events = require ( 'events' ) ; const e = new events .EventEmitter() ; e. setMaxListeners ( 3 ) ; //===========Example1 e. on ( 'event1' ,function () { console . log ( 'event1' ) ; }) e. on ( 'event1' ,function () { console . log ( 'event2' ) ; }) e. on ( 'event1' ,function () { console . log ( 'event3' ) ; }) // e.on('event1',function () { // console.log('event4'); // }) //==============call e. emit ( 'event1' ) ;

  const events = require ( 'events' ) ; const e = new events .EventEmitter() ; function Event1CallBackFun () { console . log ( 'Event1' ) ; } e. on ( 'Event1' , Event1CallBackFun ) e. on ( 'Event1' ,function () { console . log ( `new no call back function.` ) ; }) e. on ( 'Event2' ,function () { console . log ( 'Event2' ) ; }) //====call== e. emit ( 'Event1' ) ; /* * Event1 new no call back function. * */ e. emit ( 'Event2' ) ; //Event2 //==Remove Event1 try { e. removeAllListeners ( 'Event1' ) ; } catch (e) { console . log (e) } //e.removeListener('Event1',Event1CallBackFun) //====call== e. emit ( 'Event1' ) ; //no outpute e. emit ( 'Event2' ) ; //only show Event2

  const events = require ( 'events' ) ; const e = new events .EventEmitter() ; e. on ( 'click' , () => console . log ( 'Click 1' )) ; e. on ( 'click' , () => console . log ( 'Click 2' )) ; e. emit ( 'click' ) ; // Output: Click 1\nClick 2 //e.removeAllListeners('click'); try { e. removeListener () ; } catch (e) { console . log ( `Error : ${e} ` ) ; } e. emit ( 'click' ) ; // No output

  let events = require ( 'events' ) ; let e= new events .EventEmitter() ; function T () { console . log ( 'Line 7' ) ; } e. on ( 'Click' , T ) e. emit ( 'Click' ) ; //=========NOt Work // e.removeListener('Click',function () { // console.log('remove') // }); //e.removeListener('Click',T); e. emit ( 'Click' ) ; //=========Re Assign Click Event function TT () { console . log ( `Line 22` ) ; } e. on ( 'Click' , TT ) ; e. emit ( 'Click' ) ;