源码 插值语法实现
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <title>姓名案例_插值语法实现</title>
        
        <script type="text/javascript" src="../js/vue.js"></script>
    </head>
    <body>
        
        <div id="root">
            姓:<input type="text" v-model="firstName"> <br/><br/>
            名:<input type="text" v-model="lastName"> <br/><br/>
            全名:<span>{{firstName + '-' + lastName}}</span><br/>
            全名:<span>{{firstName}}-{{lastName}}</span>
        </div>
    </body>
    <script type="text/javascript">
        Vue.config.productionTip = false 
        new Vue({
            el:'#root',
            data:{
                firstName:'张',
                lastName:'三'
            }
        })
    </script>
</html>
源码 method方法实现
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <title>姓名案例_methods实现</title>
        
        <script type="text/javascript" src="../js/vue.js"></script>
    </head>
    <body>
        
        <div id="root">
            姓:<input type="text" v-model="firstName"> <br/><br/>
            名:<input type="text" v-model="lastName"> <br/><br/>
            
            全名:<span>{{fullName()}}</span>
        </div>
    </body>
    <script type="text/javascript">
        Vue.config.productionTip = false 
        const vm = new Vue({
            el:'#root',
            data:{
                firstName:'张',
                lastName:'三'
            },
            methods: {
                fullName(){
                    console.log('@---fullName')
                    
                    return this.firstName + '-' + this.lastName
                }
            },
        })
    </script>
</html>