VUE life cycle (overall process from top to bottom)
****The constructor generates Vue real columns
Event and lifecycle hook initialization
beforeCreate: Called before data initialization and Events event configuration
created: After the data has been initialized, the attribute event callback is calculated, but the DOM tree is not mounted.
Determine whether there is an el object and mount it if none
Whether there is a template => If yes, convert the template to render and replace it, and use it to render to create a DOM tree
=> If no, compile the el object as the outer html as a template
beforeMount: The render function is called for the first time before mounting, generates a virtual DON,
creates $el (virtual) under the vue instance and replaces it with the real DOM
mounted: The mounting is complete, the DOM tree has been rendered to the page, and DOM operations can be performed
beforeUpdate: The data is updated to be called
update: Virtual DOM re-rendering patch to re-render DOM with minimal DOM expenditure
beforeDestroy: Called before the real column is destroyed, you can also access the data of the real column here
Clear update, sub-components, event monitoring, etc.
destroyed: call after the component is destroyed****
I have read some articles to understand