var app2 = new Vue({ el: '#app-2', data: { message: '页面加载于 ' + new Date().toLocaleString() } })

下面是根据你提供的代码所画的控制流图：

+-----------------+
|                 |
|  START          |
|                 |
+-----------------+
         |
         | (create a new Vue instance)
         |
+----------------------------------+
|                                  |
|  +-----------------+             |
|  |                 |             |
|  |  CREATE NEW VUE  |             |
|  |       INSTANCE  |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (set the element property to '#app-2')
|           |                      |
|  +-----------------+             |
|  |                 |             |
|  |  SET ELEMENT     |             |
|  |    PROPERTY     |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (set the data property to an object with a message property)
|           |                      |
|  +-----------------+             |
|  |                 |             |
|  |   SET DATA       |             |
|  |   PROPERTY      |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (concatenate '页面加载于 ' and the current date and time to the message property)
|           |                      |
|  +-----------------+             |
|  |                 |             |
|  |  CONCATENATE     |             |
|  |    MESSAGE       |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (set the message property to the concatenated string)
|           |                      |
|  +-----------------+             |
|  |                 |             |
|  |   SET MESSAGE     |             |
|  |   PROPERTY      |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (render the Vue instance to the DOM)
|           |                      |
|  +-----------------+             |
|  |                 |             |
|  |     RENDER      |             |
|  |     VUE TO      |             |
|  |       THE       |             |
|  |      DOM        |             |
|  |                 |             |
|  +-----------------+             |
|           |                      |
|           | (end of the program)
|           |                      |
+------------------                |
                    |               |
                    +---------------+