javascriptasync-await

Is there a way to use Await to wait until a condition returns true?

I was working on something, and I was thinking about if I could use await() to wait until a condition returns true. Possibly something like this: await(x===true);

I don't know if you can do this, but it would be very helpful if you could! Is this possible, or no? Thank you!

Solution

  • You can implement a busy wait like this:

    console.log('begin');

async function busyWait(test) {
  const delayMs = 500;
  while(!test()) await new Promise(resolve => setTimeout(resolve, delayMs));
}

let a = 'hello';
setTimeout(() => a = 'world', 2000);

(async () => {
  await busyWait(() => a==='world')
  console.log('done');
})();