That only matters if the child components are actively attempting to optimize themselves by implementing `shouldComponentUpdate` with a shallow equality check (

That only matters if the child components are actively attempting to optimize themselves by implementing `shouldComponentUpdate` with a shallow equality check (or are PureComponents, which do the same thing). Please see this post for clarification on the actual pros and cons of creating functions in `render`: https://cdb.reacttraining.com/react-inline-functions-and-performance-bdff784f5578 https://cdb.reacttraining.com/react-inline-functions-and-per...