setTimeout(callback, delay[, ...args])

• callback <Function> 当定时器结束时调用的函数。
• delay <number> 调用 callback 之前等待的毫秒数。
• ...args <any> 调用 callback 时要传入的可选参数。
• 返回: <Timeout> 用于 clearTimeout()

在 delay 毫秒后调度单次的 callback 的执行。

callback 可能不会在精确的 delay 毫秒内被调用。 Node.js 不保证回调将触发的确切时间，也不保证它们的顺序。 回调将在尽可能接近指定的时间时调用。

当 delay 大于 2147483647 或小于 1 时，则 delay 将设置为 1。 非整数延迟被截断为整数。

如果 callback 不是函数，则将抛出 TypeError。

此方法具有可使用 util.promisify() 获得的 promise 的自定义变体。

const util = require('util');
const setTimeoutPromise = util.promisify(setTimeout);

setTimeoutPromise(40, 'foobar').then((value) => {
  // value === 'foobar'（传入的值是可选的）
  // 这是在大约 40 毫秒后执行的。
});

• callback <Function> The function to call when the timer elapses.
• delay <number> The number of milliseconds to wait before calling the callback.
• ...args <any> Optional arguments to pass when the callback is called.
• Returns: <Timeout> for use with clearTimeout()

Schedules execution of a one-time callback after delay milliseconds.

The callback will likely not be invoked in precisely delay milliseconds. Node.js makes no guarantees about the exact timing of when callbacks will fire, nor of their ordering. The callback will be called as close as possible to the time specified.

When delay is larger than 2147483647 or less than 1, the delay will be set to 1. Non-integer delays are truncated to an integer.

If callback is not a function, a TypeError will be thrown.

This method has a custom variant for promises that is available using util.promisify():

const util = require('util');
const setTimeoutPromise = util.promisify(setTimeout);

setTimeoutPromise(40, 'foobar').then((value) => {
  // value === 'foobar' (passing values is optional)
  // This is executed after about 40 milliseconds.
});