Question

我需要在javascript中有一个永无止境的循环。这几乎就像设定的间隔。但是对于每个循环，需要动态应用时间延迟。每个循环的延迟值都会发生变化。那么有可能在使用某种睡眠功能时使用吗？或者是否可以更改每次迭代的设置间隔时间？

以下代码没有给出延迟。始终采用给定的第一个值。

<script>
var someTimeoutVar = 1000;
var inc = 1;
setInterval(function() { 
    inc++;
    someTimeoutVar = inc * 1000;
    console.log(someTimeoutVar);
}, someTimeoutVar)
</script>

Answer 1

使用setTimeout代替并保持递归调用。

function someLoop() {
    var nextExecutionTime = calc();
    setTimeout(someLoop, nextExecutionTime);
}

Answer 2

您可以使用：

setInterval(expression, someTimeoutVar);

然后根据需要更改someTimeoutVar

Answer 3

function repeatedOperation() {
  /* Do operations here. */
  /* ... */
  /* You can return something if desired to help
   * the other function decide what the new timeout
   * delay should be. By default, I have set the new
   * timeout delay to be whatever is returned here
   * plus a random fuzz time between 0-1 second. */
  return 1; /* interpreted as milliseconds */
}

function updateTimeout(result) {
  /* Compute new timeout value here based on the
   * result returned by the operation.
   * You can use whatever calculation here that you want.
   * I don't know how you want to decide upon a new
   * timeout value, so I am just giving a random
   * example that calculates a new time out value
   * based on the return value of the repeated operation
   * plus an additional random number. */
  return Math.round(result + 1000*Math.random());
  /* This might have been NaN. We'll deal with that later. */
}

function proxyInterval(oper, delay) {
  var timeout = delay(oper());
  setTimeout(function() { proxyInterval(oper, delay); }, timeout-0 || 1000);
  /* Note: timeout-0 || 1000 is just in case a non-numeric
   * timeout was returned by the operation. We also
   * could use a "try" statement, but that would make
   * debugging a bad repeated operation more difficult. */
}

/* This is how to use the above code: */

proxyInterval(repeatedOperation, updateTimeout);

javascript while循环或设置间隔与动态延迟

3 个答案: