Programming Week 10 Flashcards

Array Access

• Use System.out.println(ar[ar.length - 1]); to print the last element of the array ar.
• Accessing ar[ar.length] is out of bounds and will result in an error.

Method Behavior

• Method signature void m(int[] ar) can change values in the array ar directly since arrays are reference types.

Array Properties

• vals.length for the 2D array vals is 4, indicating the number of arrays it contains.

Data Types

• The data type of num in int[] num = new int; is int, indicating an integer array.

Constructors

• Constructors share the same name as the class they belong to.
• A class can have any number of constructors, allowing for different ways to instantiate objects.

Accessor Methods

• Accessor instance methods typically begin with "get" for returning values or "is" depending on the return type.

Class Instantiation

• To instantiate a Rectangle object, the correct syntax is Rectangle myRectangle = new Rectangle(10, 12);.

Default Constructor

• A valid default constructor for Clock is public Clock() { setTime(0, 0, 0); }.

Public Methods

• The method setTime(int, int, int) is public and does not return anything.

Valid Method Calls

• The valid set of statements to call methods on a Rectangle object is:
  • bigRect.area();
  • bigRect.perimeter();
  • bigRect.print();

Class Relationships

• The "is-A" relationship occurs when a subclass is a type of its superclass, indicating a hierarchy.

Inheritance

• Inheritance allows for the expression of relationships between classes, promoting code reuse.

Method Overloading

• When overloading a method in a subclass, you must change the number, type, or order of parameters.

Constructor Requirement

• When defining a subclass without a constructor, its superclass must either have no constructors defined or have a default (no-arg) constructor.

UML Diagrams

• The method toString() serves to provide a string representation of the object.

Superclass Constructors

• A subclass constructor with Student(String name, long id) will compile if the superclass Person has a default or no-arg constructor.

Object Reference Output

• The method used to print an object in the format pete is Person@addbf1 is toString().

ArrayList Requirement

• To use ArrayList, import the class from the java.util package.

Test your understanding of programming concepts with these flashcards for Week 10. Focused on printing elements from arrays, these flashcards provide both questions and definitions to enhance your learning. Perfect for students looking to reinforce their knowledge in this crucial area of programming.