Question

我想在console.log('Procccess Ends');函数解析后使用异步/等待来运行updateGuider。

类似于以下代码：

tutor();

async function tutor(){
console.log('tutor function initiated..');
// wait until updateGuider function resolves
await updateGuider('default');
// The expected result is to reach this line after updateGuider resolves, but we can't so far!
console.log('Procccess Ends');


}

function updateGuider(state){    
  return new Promise((resolve) => { 

    if(state == 'done'){
       console.log('updateGuider has been resolved!');
       resolve();    
    }

    switch(state) {
          case 'default':
          speak();
          break;         
    }
    
    });  
}


async function speak(){
  
   setTimeout(function(){
      //after 5 seconds we resolve the updateGuider from speak function
      updateGuider('done')      
   },5000)
  
}

但是即使我们解决了updateGuider，它也不会运行console.log('Procccess Ends');

我想念什么以及如何解决？

如何从updateGuider解析speak？

更新：感谢@h2ooooooo，此代码有效，但我不知道它如何工作，如果这是一个好的解决方案以及它如何工作，请您帮帮我！

tutor();

async function tutor(){
console.log('tutor function initiated..');
// wait until updateGuider function resolves
await updateGuider('default');
// The expected result is to reach this line after updateGuider resolves, but we can't so far!
console.log('Procccess Ends');


}

function updateGuider(state){    
  return new Promise((resolve) => { 

    switch(state) {
          case 'default':
          speak(resolve);
          break;         
    }
    
    });  
}


async function speak(resolve){
  
   setTimeout(function(){
      //after 5 seconds we resolve the updateGuider from speak function
     console.log('entered speak')
     resolve();      
   },5000)
  
}

Answer 1

每次调用updateGuider时，您将返回不同的承诺。严格来说，您无法像这样解决updaterGuide。另外，除非您等待异步函数中的某些操作，否则它什么也不做，因此，speak当前没有理由进行异步。这不是完美的方法，但是您可以找到问题的要点。


function updateGuider(state){    
  return new Promise((resolve) => { 

    if(state == 'done'){
       console.log('updateGuider has been resolved!');
       resolve();    
    }

    switch(state) {
          case 'default':
          speak(resolve);
          break;         
    }

    });  
}

function speak(resolve){

   setTimeout(function(){
      //after 5 seconds we resolve the updateGuider from speak function
      resolve()    
   },5000)

}

兑现诺言不如预期

1 个答案: