examples of the use of the spread operator

spread.js

case TOGGLE_TWEET:
      return {
        ...state, 
        [action.id]:  {
          ...state[action.id],
          likes: action.hasLiked === true
            ? state[action.id].likes.filter( (uid) =>  uid !== action.authedUser )
            : state[action.id].likes.concat([action.authedUser])
        }
      }
const deck = {
      ...this.state.deck,
      questions: [...this.state.deck.questions, { question, answer }]
    };

  deletePost = (id) => {
      this.setState({
        posts: {
        ...this.state.posts,
        [id] : {
          ...this.state.posts[id],
          deleted: true
          }
        }
      })
    }