Why can't click events in js be executed repeatedly?

The click event in JavaScript cannot be executed repeatedly because of the event bubbling mechanism. To solve this problem, you can take the following measures: Use event capture: Specify an event listener to fire before the event bubbles up. Handing over events: Use event.stopPropagation() to stop event bubbling. Use a timer: trigger the event listener again after some time.

Why can’t click events in JavaScript be executed repeatedly?

In JavaScript, a click event can only be triggered when an element is clicked for the first time. This is due to the event bubbling mechanism, where events bubble up from the triggering element to the root element of the document.

Event bubbling

When the user clicks on an element, the event fires on that element first. The event then continues to bubble to its parent element, to its parent element, and so on until it reaches the root element of the document.

If an element has multiple click event listeners, only the first listener will respond. This is because when the event bubbles up to that element, other listeners have already been fired.

Solution

There are several ways to avoid repeated execution of click events in JavaScript:

• Use event capture: By using the third parameter useCapture of the addEventListener() method, you can specify whether the event listener is triggered before the event bubbles up. Setting useCapture to true will trigger the listener before the event bubbles up.
• Handover event: You can use the event.stopPropagation() method to stop the event from bubbling. This will prevent the event from bubbling further up to the root element of the document.
• Using a timer: You can use the setTimeout() or setInterval() function to trigger the event listener again after a period of time. This will allow subsequent click events to be executed after the first click event fires.

Example

Use event capture to allow repeated execution of click events:

<code class="javascript">element.addEventListener('click', function() {
  // 代码...
}, true);</code>

Use event.stopPropagation() To stop the event from bubbling up:

<code class="javascript">element.addEventListener('click', function(event) {
  event.stopPropagation();
  // 代码...
});</code>

Use a timer to trigger the click event again:

<code class="javascript">let timer;

element.addEventListener('click', function() {
  clearTimeout(timer);
  // 代码...
  
  timer = setTimeout(function() {
    element.click();
  }, 500); // 500 毫秒后再次触发点击事件
});</code>

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