**Course Title:** Introduction to Programming with Scratch **Section Title:** Introduction to Lists and Data Structures in Scratch **Topic:** Storing and Displaying Data from Lists in Games and Projects In the previous topics, you learned how to create and manage lists in Scratch. Now, let's dive into how to store and display data from lists in your games and projects. **Why Store and Display Data from Lists?** Lists in Scratch can be used to store a wide range of data, from player scores and high scores to inventory items and levels. Being able to store and display data from lists is crucial for creating engaging and interactive games and projects. **Storing Data in Lists** To store data in a list, you can use the `add to` and `insert at` blocks from the `Lists` category. The `add to` block adds a new item to the end of the list, while the `insert at` block adds a new item at a specific position in the list. For example, let's say you want to store player scores in a list. Each time the player completes a level, you can add their score to the list using the `add to` block. * Create a new list called `scores` by clicking on the `Lists` category and then clicking on the `Make a List` button. * Drag and drop the `add to` block into your script and connect it to the `scores` list. * Set the `value` field in the block to the player's current score using the `=` sign. Here's what the code might look like: ```scratch When green flag clicked add [score] to [scores v] ``` **Displaying Data from Lists** To display data from a list, you can use the `item` block from the `Lists` category. This block retrieves a specific item from the list and displays it on the screen. For example, let's say you want to display the player's top score on the screen. You can use the `item` block to retrieve the first item in the `scores` list (which is the most recent score) and display it. * Drag and drop the `item` block into your script and connect it to the `scores` list. * Set the `index` field in the block to 1, which represents the first item in the list. * Drag and drop a `set` block into your script and connect it to a text sprite or a speech bubble sprite to display the score. Here's what the code might look like: ```scratch When green flag clicked set [score] to (item [1] of [scores v]) say [score] ``` **Example Project: High Score Tracker** Let's create a simple high score tracker game that demonstrates how to store and display data from a list. * Create a new sprite for the game and add a script that keeps track of the player's score. * Create a list called `scores` to store the player's high scores. * Use the `add to` block to add the player's score to the `scores` list each time the player completes a level. * Use the `item` block to retrieve the player's top score from the `scores` list and display it on the screen. Here's what the code might look like: ```scratch When green flag clicked set [score] to [0] add [score] to [scores v] end When space key pressed change [score] by [1] add [score] to [scores v] end When green flag clicked set [high score] to (item [1] of [scores v]) say [high score] ``` **Key Concepts** * Lists in Scratch can store a wide range of data, from player scores and high scores to inventory items and levels. * The `add to` block adds a new item to the end of the list. * The `insert at` block adds a new item at a specific position in the list. * The `item` block retrieves a specific item from the list and displays it on the screen. **Practical Takeaways** * Use lists to store data in your games and projects, such as player scores and high scores. * Use the `add to` block to add new items to the end of the list. * Use the `insert at` block to add new items at specific positions in the list. * Use the `item` block to retrieve specific items from the list and display them on the screen. **Conclusion** In this topic, you learned how to store and display data from lists in your games and projects. Remember to use lists to store data, use the `add to` block to add new items to the end of the list, use the `insert at` block to add new items at specific positions in the list, and use the `item` block to retrieve specific items from the list and display them on the screen. **Recommended Activity** Create a simple high score tracker game that demonstrates how to store and display data from a list. **Additional Resources** For more information on lists and data structures in Scratch, check out the official [Scratch documentation](https://en.scratch-wiki.info/wiki/List_(value)). **Leave a comment below if you have any questions or need further clarification on this topic!** **What's next?** In our next topic, we'll cover **Common issues in Scratch projects and how to identify them**. Stay tuned!

When green flag clicked
  add [score] to [scores v]

When green flag clicked
  set [score] to (item [1] of [scores v])
  say [score]

When green flag clicked
  set [score] to [0]
  add [score] to [scores v]
end

When space key pressed
  change [score] by [1]
  add [score] to [scores v]
end

When green flag clicked
  set [high score] to (item [1] of [scores v])
  say [high score]