The Component in React has two problems
- The component will rerender () even if the state data is not changed as long as setState() is executed
- When the current component rerenders (), it automatically rerenders the children, which can be inefficient if they don’t use anything from the parent.
Causes of the above problems
- ShouldComponentUpdate () always returns true
Efficient practice
- Rerender only if the component’s state or props data changes
The solution to the problem
- Determine render by manually judging shouldComponentUpdate
- Change Component introduced from React to PureComponent (both parent and child components need to be changed)
