ReactJs Components

• clearly depicts the issue with keys when they are not used correctly
• key issue with list
  • key is essential for arrays when doing updates in the ui -> adding an item in the end of the list works well
  • in the beginning of the list react works worse, for that we should use key attribute
    • the most used keys comes from the data
    • when there is no data, using a math.random can be an option but it has a drawback, index is also not recommended as it can impact negatively performance
      • indexes have a problem when they are prone to change (such as a reverse function), using index won’t update the state accordingly
• controlled vs uncontrolled components
  • simple form (uncontrolled)
  • controlled form
• contexts
  • solves the prop drilling problem