프로마이스 연습

doSomething()

.then( result => doSomethingElse(result) )

.then(newResult => doThirdThing(newResult))

.then(finalResult => { console.log(`Got the final result: ${finalResult}`); })

.catch(failureCallback);

function doSomething(){

return new Promise(function(resolve,reject){

setTimeout(function() {

console.log('doSomething');

resolve('result1');

}, 1000);

})

}

function doSomethingElse(){

return new Promise(function(resolve,reject){

setTimeout(function() {

console.log('doSomethingElse');

resolve('result2');

}, 1000);

})

}

function doThirdThing(){

return new Promise(function(resolve,reject){

setTimeout(function() {

console.log('doThirdThing');

resolve('result3');

}, 1000);

})

}

function failureCallback(){

console.log('call last call');

}

결과

doSomething

doSomethingElse

doThirdThing

Got the final result: result3