这里写的是一个旋转按钮使用的是elementPlus

vue3动态class三目预算:class="isRotated ? 'rotate' : 'reverseRotate'"通过点击事件给变量取反来实现class样切换

HTML

 <div class="numE" @click="numE">
    <el-icon ref="numElement" color="#fff" size="30px" :class="isRotated ? 'rotate' : 'reverseRotate'">
     <Expand />
    </el-icon>
 </div>

CSS

.rotate,
.reverseRotate {
    transition: transform 0.5s ease;
}
.rotate {
    transform: rotate(180deg);
}
.reverseRotate {
    transform: rotate(0deg);
}

JS

import { ref } from 'vue'
let isRotated = ref(false)
let numE = () => {
    isRotated.value = !isRotated.value;
}