This unit introduces a new type of data: reference data. This unit builds on students’ ability to write expressions by introducing them to Math class methods to write expressions for generating random numbers and other more complex operations. In addition, strings and the existing methods within the String class are an important topic within this unit.

This unit focuses on selection, which is represented in a program by using conditional statements. Conditional statements give the program the ability to decide and respond appropriately and are a critical aspect of any nontrivial computer program. In addition to learning the syntax and proper use of conditional statements, students will build on the introduction of Boolean variables by writing Boolean expressions with relational and logical operators.

This unit focuses on iteration using while and for loops. This unit introduces several standard algorithms that use iteration. Knowledge of standard algorithms makes solving similar problems easier, as algorithms can be modified or combined to suit new situations.

This unit will pull together information from all previous units to create new, user-defined reference data types in the form of classes. The ability to accurately model real-world entities in a computer program is a large part of what makes computer science so powerful. This unit focuses on identifying appropriate behaviors and attributes of real-world entities and organizing these into classes. Students will build on what they learn in this unit to represent relationships between classes through hierarchies.

This unit focuses on data structures, which are used to represent collections of related data using a single variable rather than multiple variables. Just as there are useful standard algorithms when dealing with primitive data, there are standard algorithms to use with data structures. In this unit, students apply standard algorithms to arrays.

In this unit, students learn about the limitations of arrays and are introduced to a new data structure – ArrayLists. Students are asked to compare the two data structures and implement programs that utilize each.

In this unit, students learn how to store data in increasingly complex ways by introducing them to the 2D arrays. Students will learn standard algorithms to utilize and search 2D arrays, as well as ways to use them effectively in their programs.

In this unit, students will learn how to recognize common attributes and behaviors that can be used in a superclass and will then create a hierarchy by writing subclasses to extend a superclass. Recognizing and utilizing existing hierarchies will help students create more readable and maintainable programs.

In this unit, students will learn how to write simple recursive methods and determine the purpose or output of a recursive method by tracing.