text: var app = new Vue({
      el : '#app',
      data : {
          firstName : "",
          lastName : ""
      },
      computed : {
          // fullName : function () {
          //     // console.log('12222');
              
          //     return this.firstName + " " + this.lastName;
          // }
          fullName : {
              // getter
              get: function () {
                  return this.firstName + ' ' + this.lastName
              },
              // setter
              set: function (newValue) {
                  var names = newValue.split(' ')
                  this.firstName = names[0]
                  this.lastName = names[names.length - 1]
              }
          }
      }
  });