示例:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <title>绑定样式</title>
        <style>
            .basic{
                width: 400px;
                height: 100px;
                border: 1px solid black;
            }
            
            .happy{
                border: 4px solid red;;
                background-color: rgba(255, 255, 0, 0.644);
                background: linear-gradient(30deg,yellow,pink,orange,yellow);
            }
            .sad{
                border: 4px dashed rgb(2, 197, 2);
                background-color: gray;
            }
            .normal{
                background-color: skyblue;
            }

            .atguigu1{
                background-color: yellowgreen;
            }
            .atguigu2{
                font-size: 30px;
                text-shadow:2px 2px 10px red;
            }
            .atguigu3{
                border-radius: 20px;
            }
        </style>
        <script type="text/javascript" src="../js/vue.js"></script>
    </head>
    <body>
        <!-- 
            绑定样式:
                    1. class样式
                                写法:class="xxx" xxx可以是字符串、对象、数组。
                                        字符串写法适用于:类名不确定,要动态获取。
                                        对象写法适用于:要绑定多个样式,个数不确定,名字也不确定。
                                        数组写法适用于:要绑定多个样式,个数确定,名字也确定,但不确定用不用。
                    2. style样式
                                :style="{fontSize: xxx}"其中xxx是动态值。
                                :style="[a,b]"其中a、b是样式对象。
        -->
        <!-- 准备好一个容器-->
        <div id="root">
            <!-- 绑定class样式--字符串写法,适用于:样式的类名不确定,需要动态指定 -->
            <div class="basic" :class="mood" @click="changeMood">{{name}}</div> <br/><br/>

            <!-- 绑定class样式--数组写法,适用于:要绑定的样式个数不确定、名字也不确定 -->
            <div class="basic" :class="classArr">{{name}}</div> <br/><br/>

            <!-- 绑定class样式--对象写法,适用于:要绑定的样式个数确定、名字也确定,但要动态决定用不用 -->
            <div class="basic" :class="classObj">{{name}}</div> <br/><br/>

            <!-- 绑定style样式--对象写法 -->
            <div class="basic" :style="styleObj">{{name}}</div> <br/><br/>
            <!-- 绑定style样式--数组写法 -->
            <div class="basic" :style="styleArr">{{name}}</div>
        </div>
    </body>

    <script type="text/javascript">
        Vue.config.productionTip = false
        
        const vm = new Vue({
            el:'#root',
            data:{
                name:'尚硅谷',
                mood:'normal',
                classArr:['atguigu1','atguigu2','atguigu3'],
                classObj:{
                    atguigu1:false,
                    atguigu2:false,
                },
                styleObj:{
                    fontSize: '40px',
                    color:'red',
                },
                styleObj2:{
                    backgroundColor:'orange'
                },
                styleArr:[
                    {
                        fontSize: '40px',
                        color:'blue',
                    },
                    {
                        backgroundColor:'gray'
                    }
                ]
            },
            methods: {
                changeMood(){
                    const arr = ['happy','sad','normal']
                    const index = Math.floor(Math.random()*3)
                    this.mood = arr[index]
                }
            },
        })
    </script>
   
</html>