Vue之计算属性computed

<div id="app">

        <input type="text" v-model="m1">

        {{msg}}

    </div>

    <script>

        var m = {

            m1: 'hello world!'

        };

        var vm = new Vue({

            el: '#app',

            data: m,

            // 用下面这种写法，调用msg时需要加()

            methods: {

                // msg: function(){

                //     return this.m1.split('').reverse().join('');

                // }

            },

            // 用下面这种计算属性写法，调用msg时不需要加()

            computed: {

                msg: function(){

                    return this.m1.split('').reverse().join('');

                }

            }

        })

    </script>