# 三. 为什么要用Promise
function successCallback(result) {
console.log("声音文件创建成功:"+ result);
}
function failureCallback(error) {
console.log("声音文件创建失败:"+ error);
}
createAudioFileAsync(audioSettings, successCallback, failureCallback)
const promise = createAudioFileAsync(audioSettings);
setTimeout(()=> {
promise.then(successCallback, failureCallback);
J, 3000);
doSomething(function(result) {
doSomethingElse(result, function(newResult) {
doThirdThing(newResult, function(finalResult) {
console.log('Got the final result:' + finalResult)
}, failureCallback)
}, failureCallback)
}, failureCallback);
doSomething()
.then(function(result) {
return doSomethingElse(result)
})
.then(function(newResult){
return doThirdThing(newResult)
})
.then(function(finalResult) {
console.log('Got the final result: '+ finalResult)
})
.catch(failureCallback)
async function request(){
try {
const result = await dosomething()
const newResult = await doSomethingElse(result)
const finalResult = await doThirdThing(newResult)
console.log('Got the final result:' + finalResult)
} catch (error){
failureCallback(error)
}
}