需要帮助在 JavaScript 中使用“For”语句编写循环代码

Question

我需要使用循环从 10 到 0 进行倒计时。循环应该替换需要重复 10X 的代码。我还需要在 HTML 中向用户显示倒计时。救命！

<script>
       
function StartTheCountdown()
{ 
     var Countdown = 10;
     // Used to keep track of actual time.
     // 1000 = 1 second because we are using milliseconds.
    var timeout = 10000;
    setTimeout(() => {
    document.getElementById("CountDownDisplay").innerHTML = "Blastoff!";
    Countdown = Countdown - 1;
    }, timeout)
    timeout = timeout - 1000;
    // We need to do this 10 times **************************************
    setTimeout(() => {
    document.getElementById("CountDownDisplay").innerHTML = Countdown;
    Countdown = Countdown - 1;
    }, timeout)
    timeout = timeout - 1000; 
}
    </script>

Answer 1

使用setTimeout重复调用函数，直到count为零，然后显示消息。

// Cache your element
const div = document.querySelector('div');

// Initialise your count to 10
function countdown(count = 10) {

  // Update your element textContent
  div.textContent = `T-minus: ${count}`;

  // Call the function again if the count
  // is greater than 0 with a decremented count
  if (count > 0) {
    setTimeout(countdown, 1000, --count);

  // Otherwise update the textContent of the
  // element with a message
  } else {
    div.textContent = 'Blast off!';
  }
}

countdown();

<div></div>

其他文档

• Template/string literals