- 计算属性默认只有 getter ,不过在需要时你也可以提供一个 setter getter 用于监控属性变化时触发。
 set可选,当computed属性自身被赋值时触发
    <div id="app">
        {{fullName}}
    </div>
    <script>
        var vm = new Vue({
            el: "#app",
            data: {
                firstName: "Dell",
                lastName: "Lee"
            },
            computed: {
                fullName: {
                    get: function () {
                        return this.firstName + " " + this.lastName
                    },
                    set: function (value) {
                        var arr = value.split(" ");
                        this.firstName = arr[0];
                        this.lastName = arr[1];
                    }
                }
            }
        })
    </script>
来源:https://blog.csdn.net/HuangsTing/article/details/99411880