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javascript - 如何解决 Uncaught TypeError: Cannot read properties of undefined (reading 'toggle')

问题描述

如果有人将鼠标悬停在标签上，我想为此元素添加一个“-js-expanded”类。我怎样才能做到这一点？

<a href="" target="_self" class="sticky-cta" onmouseover="myFunction()" >
  <span class="sticky-label">GET STARTED</span>
  <i class="icon-features-productivity"></i>
</a>

  function myFunction () {
      this.classList.toggle("-js-expanded");
  }

  .-js-expanded {
  color: red;
  }

标签： javascript

解决方案

 function myFunction (element) {
      element.classList.toggle("-js-expanded");
  }
.-js-expanded {
  color: red;
  }
<a href="" target="_self" class="sticky-cta" onmouseover="myFunction(this)" >
  <span class="sticky-label">GET STARTED</span>
  <i class="icon-features-productivity"></i>
</a>

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