1、组件和父组件的生命周期执行顺序
App-------beforeCreate
App-------created
App-------beforeMount
组件beforeCreate
组件created
组件beforeMount
组件mounted
App-------mounted
1、组件和父组件的生命周期执行顺序
App-------beforeCreate
App-------created
App-------beforeMount
组件beforeCreate
组件created
组件beforeMount
组件mounted
App-------mounted