Sprite Arrays
Summary
Materials
Instructional Activities and Classroom Assessments
- Introduce Sprite Arrays (10 minutes)
- Activity: Create and Modify Sprite Arrays (40 minutes)
- Extension: Tilemaps & Arrays
- Reflection/Homework
Learning Objectives
- AAP-1.A Represent a value with a variable. 3.A
- AAP-1.B Determine the value of a variable as a result of an assignment. 4.B
- AAP-1.C Represent a list or string using a variable. 3.A
- AAP-1.D For data abstraction:
- AAP-2.N For list operations:
- AAP-2.O For algorithms involving elements of a list:
- AAP-2.K For iteration:
- a. Write iteration statements. 2.B
- b. Determine the result or side effect of iteration statements. 4.B
- AAP-3.E For generating random values:
- a. Write expressions to generate possible values. 2.B
- b. Evaluate expressions to determine the possible results. 4.B 2.B
Essential Knowledge
- AAP-1.A.1 A variable is an abstraction inside a program that can hold a value. Each variable has associated data storage that represents one value at a time, but that value can be a list or other collection that in turn contains multiple values.
- AAP-1.A.2 Using meaningful variable names helps with the readability of program code and understanding of what values are represented by the variables.
- AAP-1.A.3 Some programming languages provide types to represent data, which are referenced using variables. These types include numbers, Booleans, lists, and strings.
- AAP-1.A.4 Some values are better suited to representation using one type of datum rather than another.
- AAP-1.C.1 A list is an ordered sequence of elements. For example, [value1, value2, value3, ...] describes a list where value1 is the first element, value2 is the second element, value3 is the third element, and so on.
- AAP-1.C.2 An element is an individual value in a list that is assigned a unique index.
- AAP-1.C.3 An index is a common method for referencing the elements in a list or string using natural numbers.
- AAP-1.D.3 Data abstractions can be created using lists.
- AAP-1.D.4 Developing a data abstraction to implement in a program can result in a program that is easier to develop and maintain.
- AAP-1.D.5 Data abstractions often contain different types of elements.
- AAP-1.D.6 The use of lists allows multiple related items to be treated as a single value. Lists are referred to by different names, such as array, depending on the programming language.
- AAP-2.N.1 The exam reference sheet provides basic operations on lists, including:
§ accessing an element by index Text: aList[i] Block: aList i accesses the element of aList at index i. The first element of aList is at index 1 and is accessed using the notation aList[1].
§ assigning a value of an element of a list to a variable Text: X ← aList [i] Block: X aList i assigns the value of aList[i] to the variable X.
§ assigning a value to an element of a list Text: aList[i] ← X Block: aList ix assigns the value of X to aList[i]. Text: aList[i] ← aList[j] Block: aListaList ij assigns the value of aList[j] to aList[i].
§ inserting elements at a given index Text: INSERT(aList, i, value) Block: aList, i, valueINSERT shifts to the right any values in aList at indices greater than or equal to i. The length of the list is increased by 1, and value is placed at index i in aList.
§ adding elements to the end of the list Text: APPEND(aList, value) Block: APPEND aList, value increases the length of aList by 1, and value is placed at the end of aList.
§ removing elements Text: REMOVE(aList, i) Block: REMOVE aList, i removes the item at index i in aList and shifts to the left any values at indices greater than i. The length of aList is decreased by 1.
§ determining the length of a list Text: LENGTH(aList) Block: LENGTH aList evaluates to the number of elements currently in aList. - AAP-2.N.2 List procedures are implemented in accordance with the syntax rules of the programming language.
- AAP-2.O.1 Traversing a list can be a complete traversal, where all elements in the list are accessed, or a partial traversal, where only a portion of elements are accessed.
XEXCLUSIONSTATEMENT(EKAAP-2.O.1): Traversing multiple lists at the same time using the same index for both (parallel traversals) is outside the scope of this course and the AP Exam. - AAP-2.K.1 Iteration statements change the sequential flow of control by repeating a set of statements zero or more times, until a stopping condition is met.
- AAP-2.K.2 The exam reference sheet provides
- Text: REPEAT n TIMES { <block of statements> }
- Block: REPEAT n TIMES block of statements in which the block of statements is executed n times.
- AAP-3.E.1 The exam reference sheet provides RANDOM(a, b) Block: RANDOM a, b which generates and returns a random integer from a to b, inclusive. Each result is equally likely to occur. For example, RANDOM(1, 3) could return 1, 2, or 3.
Details
1. Introduction to Sprite Arrays (10 minutes)
- Define array of sprites.
- Explain how sprite arrays can be used.
- Demonstrate how to create sprite arrays in MakeCode.
2. Activity: Arrays of Sprites (40 minutes)
- Direct students to the Array of Sprites page.
- Students will go to Activity: Arrays of Sprites (makecode.com).
- Instruct students to complete Practice tasks 1, 2 and 3.
- Encourage students to publish their work and paste the links on their Array of Sprites page.
3. Extension
- Encourage students to use JavaScript or Python to create the projects from Task 1, 2 and 3.
- You can also encourage students to incorporate these concepts into an existing project.
4. Reflection/Homework
If you run out of time, you may also assign this as individual homework. Students should complete their reflection in their OneNote.
- How could using arrays of sprites influence the way you design games? List at least two ways.
- How is using arrays of sprites of kind easier than keeping track of all the sprites in an array manually?