Version

3.0.2

Reproduction link

https://jsfiddle.net/starfishing/6zc71eth/1/

Steps to reproduce

Declare subcomponent ButtonDemo in a new js file， Introduce child components in parent components。click child component and watch value change

What is expected?

value Increase

What is actually happening?

The component is re-rendered every time and overwrites the modified value

1. browsers don't support jsx
2. in html you need to use kebab-case for tag names
3. move value = Vue.ref(1) outside the render function or don't use functional components

https://jsfiddle.net/bpzsqf2k/

1. browsers don't support jsx
2. in html you need to use kebab-case for tag names
3. move value = Vue.ref(1) outside the render function or don't use functional components

https://jsfiddle.net/bpzsqf2k/

Does the function component support ref or other ways to maintain its own state, like react useState in function component

maintain its own state,

functional components in Vue are stateless