How do you change ids of an array in a switch statement (redux reducer)?

Question

So I have an array of todos. When I remove a todo I am trying to change the id's of the rest of the items so for example todo[1] also has an id of 1. This is not the case if I have 3 items and remove the first one as the second item will have an id of 2 even though it should be 1.

This is what I currently have-

case REMOVE_TODO: {
      const newList = state.todos.filter(item => item.id !== action.id);
      for (let i = 0, newId = 0; i > newList.length; i++, newId++) {
        newList[i].id = newId;
        console.log(newList[i].id); //nothing gets logged
      }
      return {
      ...state,
      todos: newList
      };
    }

Instead of correctly changing the item ids nothing happens and even when I console log the id of what I just changed, nothing happens and nothing changes.

Answer 1

Looks like a problem with your iterator in the for loop. i > newList.length should be i < newList.length . Also you could use map to loop over the newList and get a newer set of array.

Answer 2

you can do without the loop . This will be good practice when you have a bunch of data.

const index = state.todos.findIndex(item => item.id == action.id);
const newList = state.todos.splice(index,1);
return {
      ...state,
      todos: newList
      };