How to update single value inside specific array item in redux

Question

I have an issue where re-rendering of state causes ui issues and was suggested to only update specific value inside my reducer to reduce amount of re-rendering on a page.

Answer 1

You can use map. Here is an example implementation:

case 'SOME_ACTION':
   return { 
       ...state, 
       contents: state.contents.map(
           (content, i) => i === 1 ? {...content, text: action.payload}
                                   : content
       )
    }