State management is a crucial concept in React. State allows components to dynamically update UI based on data changes.
However, managing state properly takes some practice. Let’s walk through the basics of handling state in React:
useState hook defines state variables:
useState accepts the initial state value and returns:
- The current state
- A function to update it
To display state in UI, simply reference the variable:
React will re-render components on state change to reflect new values.
Call the setter function to update state:
Always use the setter - don’t modify state directly.
State updates are batched for better performance:
This will only increment once instead of 3 times.
State values are guaranteed to be up-to-date if they are declared within the same component:
useStatehook declares state variables
- Reference state variables to display state
- Call setters to update state
- Updates are batched for performance
- State within a component is always fresh
Correctly managing local component state is a key React skill. State allows powerful, dynamic applications.