you have no way of determining which data has changed since the previous copy is overridden. Instead, you need to create a new copy of `myData` and change only the parts of it that need to be changed. Then you can compare the old copy of `myData` with the new one in `shouldComponentUpdate()` using triple-equals:
you have no way of determining which data has changed since the previous copy has been overwritten. Instead, you need to create a new copy of `myData` and change only the parts of it that need to be changed. Then you can compare the old copy of `myData` with the new one in `shouldComponentUpdate()` using triple-equals: