js: 添加事件监听addEventListener、移除事件监听removeEventListener

// 添加事件监听
target.addEventListener(type, listener[, options]);
target.addEventListener(type, listener[, useCapture=false]);
// 移除事件监听
target.removeEventListener(type, listener[, options]);
target.removeEventListener(type, listener[, useCapture=false]);

<button onclick="addClickEventListener()">添加事件监听</button>
<button onclick="removeClickEventListener()">移除事件监听</button>
<script>
  // 事件处理函数
  function handleEvent(event) {
    console.log(event)
  }
  // 添加事件监听
  function addClickEventListener() {
    console.log('addClickEventListener')
    document.addEventListener('click', handleEvent)
  }
  // 移除事件监听
  function removeClickEventListener() {
    console.log('removeClickEventListener')
    document.removeEventListener('click', handleEvent)
  }
</script>