Promise Fun

mdn-prmose.js

// Examples you can try in the Dev tools.
// Aim for these examples to demonstrate different ways of using promises

var p = Promise.resolve().then(function(){
    console.log('Promise resolve callback');
}, function(){
    console.log('Promise reject callback');
});

var p = Promise.reject().then(function(){
    console.log('Promise resolve callback');
}, function(){
    console.log('Promise reject callback');
});

promise-reject-1.js

Promise.reject()
.then(function() {
  console.log('resolve1');
}, function() {
  console.error('reject1');
})
.catch(function() {
	console.error('catch');	
});

-----

Promise.reject()
.then(function () {
	console.log('resolve1');
})
.then(function () {
	console.log('resolve2');
}, function () {
	console.error('reject2');
})
.catch(function () {
	console.error('catch');
})

-----

Promise.reject()
.then(function () {
	console.log('resolve1');
})
.then(function () {
	console.log('resolve2');
}, function () {
	console.error('reject2');
})
.then(function () {
	console.log('resolve3');
})
.catch(function () {
	console.error('catch');
});

-----

Promise.reject()
.then(function () {
	console.log('resolve1');
})
.then(function () {
	console.log('resolve2');
})
.then(function () {
	console.log('resolve3');
})
.catch(function () {
	console.log('catch');
})

-----

var p = Promise.reject()
.then(function () {
	console.log('resolve1');
})
.then(function () {
	console.log('resolve2');
})
.then(function () {
	console.log('resolve3');
})
.catch(function () {
	console.log('catch');
});

p

-----

promise-reject-2.js

Promise.reject()
.then(function () {
	console.log('resolve1');
}, function () {
	console.log('reject1');
})
.then(function () {
	console.log('resolve2');
}, function () {
	console.log('reject2');
})
.catch(function () {
	console.log('catch');
})

-----

Promise.reject()
.then(function () {
	console.log('resolve1');
})
.then(function () {
	console.log('resolve2');
})
.then(function () {
	console.log('resolve3');
})
.catch(function () {
	console.log('catch');
})

promise-reject-3.js

function getPromise() {
    return Promise.resolve(1);
}

function logError() {
    console.log(arguments);
}

function process () {
    return Promise.reject('Promise Rejected');
    //throw new Error('JS Error');
}

getPromise()
  .then(function (result) {
     return process(result);
  })
  .then(null, logError);

promise-return.js

Promise.resolve(1).then(function () {
  console.log(arguments);
});

// ---

Promise.resolve(1).then(function(){
   console.log(arguments);
   return 2;
}).then(function(){
   console.log(arguments);
});

// ---
Promise.resolve().then(function () {
  return 100;
})
.then(function() {
  console.log(arguments);
});
 
// ---
 
Promise.resolve(200).then(function () {
  console.log(arguments);
  return Promise.resolve(100);
})
.then(function(arg1) {
  console.log(arguments);
});
 
// ---
 
Promise.resolve().then(function () {
  return 100;
}).then(function () {
  console.log('1', arguments);
})
.then(function() {
  console.log('2', arguments);
});
 
// ---
 
Promise.resolve().then(function () {
  return 100;
})
.then(null)
.then(null)
.then(null)
.then(function() {
  console.log(arguments);
})
.then(null)
.then(function() {
  console.log(arguments);
});
 
// ---