Sample for using promises

UsingPromises

function promise(arg){
  return new Promise(function(resolve,reject){
    if(arg)
      resolve(arg);
    else
      reject('Error');
  });
}


setTimeout(function(){
  promise('Shrikanth').then(function(res){
    console.log('Hello '+res);
  },function(err){
    console.log(err)
  });
},2000);