[Vuejs]-How to get element by class name in vue.js

You can use template refs to do this:

<div class="menu" ref="menu">
  <ul>
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
  </ul>
</div>

export default {
  name: 'Button',
  data() {
    return {
      activeToggle: false
    }
  },
  methods: {
    menuToggle() {
        if (this.activeToggle == true) {
          // Access the menu using template $refs
          const menu = this.$refs.menu
        }
    },
  },
}