用三元运算方式怎么表示这些代码

<div class="cc1" v-if="str=='A'" key="A"></div>
<div class="cc2" v-if="str=='B'" key="B"></div>
<div class="cc3" v-if="str=='C'" key="C"></div>

<div :class="str=='A' ? 'cc1' : (str=='B' ? 'cc2' : 'cc3')" :key="str"></div>