Promises Basics, Promise.then() and Promise.catch() in JavaScript.

Promises Basics, Promise.then() and Promise.catch() in JavaScript. 

        Promise is an object that can create a single value for some time in the future: either a fixed value, because it is not fixed (i.e., a network error occurred).

Promises have Three states

Pending	is a initial state, means neither fulfilled nor rejected
fulfilled	Operation was completed successfully
rejected	Operation failed

console.log("this is working");
function fun1(){
  return new Promise(function(resolve, reject){
    setTimeout(()=>{
      const error = true;
      if(!error){
        console.log('your promise has been resolved');
      }else{
        console.log('your promise has not been resolved')
        reject('sorry not fullfilled');
      }
      resolve();
    },2000);
  })
}
fun1().then(function(){
  console.log('thanks for resolving');
}).catch(function(){
  console.log("very bad bro");
})

Output

this is working
 your promise has not been resolved
 very bad bro

asdf