Promises in javascript

 Promises is an object that keeps track of some event is happened or not .

--Determines what happens after the event has happened.

Promise have different states -

Example :                                                                                                        

const ids = new Promise((resolve, reject) => {

setTimeout(() => {

                                                                                         resolve([100, 200, 300, 400, 500]);

                                         }, 1500);

                 });

//Consuming promises

                                    ids.then(ids=>{//ids will store all the result

   console.log(ids); 

})

                                                 .catch(error=>{//catch is used if error has occured

   console.log(error); 

});