React functions inside render()

by

A function in the render method will be created each render which is a slight performance hit. It’s also messy if you put them in the render, which is a much bigger reason, you shouldn’t have to scroll through code in render to see the html output. Always put them on the class instead.

For stateless components, it’s probably best to keep functions outside of the main function and pass in props instead, otherwise the function will be created each render too. I haven’t tested performance so I don’t know if this is a micro-optimization but it’s worth noting.

Example:

const MyStatelessComponent = ({randomProp}) => (
    render() {
        doSomething(randomProp);

        return <div />
    }
);

doSomething = (randomProp) => {
    //Do something here
}

More Related Contents:

  1. React showing 0 instead of nothing with short-circuit (&&) conditional component
  2. ReactJS difference between stateful and stateless
  3. How to get parameter value from query string?
  4. How to create a protected route?
  5. Infinite loop in useEffect
  6. ReactJS giving error Uncaught TypeError: Super expression must either be null or a function, not undefined
  7. Warning: Text content did not match. Server: “I’m out” Client: “I’m in” div
  8. React useState cause double rendering
  9. How do I restrict the type of React Children in TypeScript, using the newly added support in TypeScript 2.3?
  10. 404 when trying to enter a react app route
  11. mobx-react observer don’t fires when I set observable
  12. ReactJS: Warning: setState(…): Cannot update during an existing state transition
  13. How to create unique keys for React elements?
  14. How to re-render flatlist?
  15. Line 0: Parsing error: Cannot read property ‘map’ of undefined
  16. How to access the “key” property from a reactjs component
  17. Use custom build output folder when using create-react-app
  18. What does ‘Only a ReactOwner can have refs.’ mean?
  19. react-router vs react-router-dom, when to use one or the other?
  20. Unexpected block statement surrounding arrow body
  21. Reactjs: Unexpected token ‘
  22. React – the right way to pass form element state to sibling/parent elements?
  23. Warning: It looks like you’re using the development build of the Firebase JS SDK
  24. Pass multiple parameters to event handlers in React
  25. What is the difference between componentWillMount and componentDidMount in ReactJS?
  26. How to resolve “Cannot use import statement outside a module” from Jest when running tests?
  27. Read the current full URL with React?
  28. VirtualizedList: You have a large list that is slow to update
  29. is it possible to React.useState(() => {}) in React?
  30. How to minimize the size of webpack’s bundle?

Leave a Comment