(Redirected from Lists)
A list (called an array in other programming languages) is a tool that can be used to store multiple pieces of information at once. It can also be defined as a variable containing multiple other variables. Although lists are similar to 1 dimensional arrays, meaning that items can not be stored in a theoretical grid, unlike most other programming languages, lists can be made to function like arrays. In fact, though called lists, they are actually resizable arrays for all practical purposes.
- Main article: List Blocks
- Add () to () — Adds an item to a list
- Delete () of () — Deletes a chosen item of a list
- Insert () at () of () — Inserts an item at a chosen point in a list
- Replace Item () of () With () — Replaces an item in a list with a new item
- () — A reporter block with few uses; however, this can be used as a Stage Monitor
- Item () of () — A reporter block that reports what text an item in a list contains
- Length of () — A reporter block that reports how many items a list contains
- () Contains () — A boolean block that checks if a list contains a given string.
Items can be added to a list manually or by programming. Items can be deleted in the same manner: manually or by programming. There is no limit to the length of an item or the amount of items a list can hold, apart from an amount sufficient to crash Scratch. However, there are few cases in which a list needs to contain that amount of information.
Some example uses for lists are as follows:
- Encoding/Decoding strings
- Artificial Intelligence
- Recording multiple values
- Conserving variables
- Saving and loading data
More Complex Uses
- Storing user-input data in Operating System simulations
- Storing AI data in games
- Allowing users to re-create past inputs
- Main article: Cloud Data
Cloud lists are a coming feature in Scratch 2.0. The values of cloud lists are stored on the Scratch servers; this is the only difference between them and regular lists. When a cloud list gets updated, it does so across all copies of the project. This makes cloud lists ideal for chatroom projects, for example.
It is possible to create a cloud list like this.
- Main article: Casting
Lists are cast to numbers and strings with a set of explicit rules depending on its contents.
- Fibonacci Generator by WeirdF
- FruitcraftRPG by Wodunne
- Random Level Generator by poopo
- Scratch Memory by spaceguy12
From the time lists were introduced, many users requested two new blocks,
hide list [list v] and
show list [list v]. Due to such high demand, they were included in Scratch 2.0.