function delay(ms) { return new Promise(resolve => setTimeout(resolve, ms)); } async function loopWithDelay() { for (let i = 0; i < 5; i++) { console.log(i); await delay(1000); // 每次循环等待1秒 } } loopWithDelay(); ...
1000); setTimeout(function timer2(){ log(`delay ${Date.now() - now} ms`); }, 5000); someOperation(); function someOperation() { // sync operation... while (Date.now() - now < 3000) {} } 当
了解eventloop的运行机制之后我们来做一道题来巩固: //阻塞方法,用于js阻塞 //delayTime单位毫秒 function wait(delayTime){ let nowStamp = new Date().getTime() const endTime = nowStamp + delayTime while (true){ if (nowStamp < endTime) { return } nowStamp = new Date().getTime() } } ...
JS是单线程的,但却能执行异步任务,这主要是因为JS中存在事件循环(Event Loop)和任务队列(Task Queue); 事件循环(是js实现异步的一种方法,也是js的执行机制):JS会创建一个类似于while(true)的循环,每执行一次循环体的过程称为Tick,每次Tick的过程就是查看是否有待处理事件,如果有则取出相关事件及回调函数放入执行...
log('max delay reached', loopBench.delay)})functionsleep (msec) {let i = const start = Date.now()while (Date.now() - start < msec) { i++ }return i}functionserve (req, res) {console.log('current delay', loopBench.delay)console.log('overLimit', loopBench.overLimit)if (loop...
() => { const delay = Date.now() - timeoutScheduled; console.log(${delay}ms have passed since I was scheduled);}, 100);// 执行一些异步操作将耗时 95mssomeAsyncOperation(() => { const startCallback = Date.now(); // 执行一些可能耗时10ms的操作 while (Date.now() - start...
使用async/await:结合Promise和async/await可以更清晰地控制异步流程。 代码语言:txt 复制 async function delay(ms) { return new Promise(resolve => setTimeout(resolve, ms)); } async function logNumbers() { for (let i = 0; i < 5; i++) { await delay(1000); console.log(i); } } logNu...
console.log(`${delay}ms have passed since I was scheduled`); }, 100); // 执行一些异步操作将耗时 95ms someAsyncOperation(() => { const startCallback = Date.now(); // 执行一些可能耗时10ms的操作 while (Date.now() - startCallback < 10) { ...
async function round() { do { await delay(2000); playerInput = input(); calculate(); } while (machineFuel > 0 && height > 0); } function delay(delay) { return new Promise(function(resolve){ setTimeout(resolve, delay); });
while (Date.now() - startCallback < 10) { // do nothing } }); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 上面的例子中,我们调用了someAsyncOperation,这个函数首先回去执行readFile方法,假设这个方法耗时95ms。接着执行read...