AP Computer Science A

Learning objectives

• Create objects using constructors and the new keyword, distinguishing from primitive declarations
• Call String methods (length, substring, indexOf, equals, compareTo) and predict their return values
• Use Math class static methods (abs, pow, sqrt, random) in expressions
• Distinguish reference equality (==) from content equality (.equals()) for objects
• Explain what null means and identify when a NullPointerException will be thrown

Learning objectives

• Evaluate boolean expressions using relational (<, >, <=, >=, ==, !=) and logical (&&, ||, !) operators
• Trace execution paths through if, if-else, and else-if chains with multiple branches
• Apply De Morgan's Laws to simplify negated compound boolean expressions
• Identify dangling-else behavior in nested conditionals and predict which branch executes
• Recognize short-circuit evaluation of && and || and its effect on side effects

Learning objectives

• Write and trace for, while, and do-while loops, predicting the number of iterations
• Apply the accumulator, counter, and sentinel patterns to solve loop-based problems
• Trace nested loop execution and calculate total iteration counts
• Identify and fix off-by-one errors caused by boundary conditions (< vs <=, starting at 0 vs 1)
• Convert between equivalent for and while loop structures

Learning objectives

• Design classes with private instance variables and public methods following encapsulation principles
• Write constructors including overloaded constructors and constructor chaining with this()
• Implement accessor (getter) and mutator (setter) methods with appropriate access modifiers
• Distinguish static members from instance members and explain when to use each
• Use the this keyword to resolve ambiguity between parameters and instance variables

Learning objectives

• Declare, create, and initialize one-dimensional arrays with both literal and new syntax
• Traverse arrays using standard for loops and enhanced for-each loops
• Implement common array algorithms: sum, average, min/max, linear search, and selection sort
• Identify and prevent ArrayIndexOutOfBoundsException caused by incorrect loop bounds
• Pass arrays to methods and explain that arrays are passed by reference in Java

Learning objectives

• Create and manipulate ArrayLists using add, remove, get, set, and size methods
• Apply autoboxing and unboxing with ArrayList<Integer> and other wrapper types
• Avoid the index-shifting bug when removing elements during forward traversal
• Compare arrays and ArrayLists and choose the appropriate data structure for a given problem
• Use ArrayList as a parameter and return type in method signatures

Learning objectives

• Declare and initialize 2D arrays using both literal and nested new syntax
• Traverse 2D arrays in row-major and column-major order using nested for loops
• Access individual elements using [row][col] indexing and explain why order matters
• Implement 2D array algorithms: row/column sums, search, transpose, and boundary checks
• Handle ragged (jagged) arrays where rows have different lengths

Learning objectives

• Create subclasses using extends and call superclass constructors with super()
• Override methods and distinguish method overriding from method overloading
• Apply polymorphism: assign subclass objects to superclass reference variables and predict dynamic dispatch
• Use abstract classes and methods to define contracts that subclasses must fulfill
• Explain the Object class as the root of Java's class hierarchy (toString, equals)

Learning objectives

• Identify base cases and recursive cases, and explain why both are necessary
• Trace recursive method execution using a call stack diagram
• Write recursive solutions for factorial, Fibonacci, binary search, and String processing problems
• Compare recursive and iterative approaches in terms of clarity, correctness, and efficiency
• Identify when recursion leads to stack overflow and how to prevent it