- A template for creating objects which describes both the data known by each object and the methods which operate on those data.
- A particular kind of data item, as defined by the values it can take, the programming language used, or the operations that can be performed on it (Oxford University, 2013). Also: data type.
- The combination of data and the operations that act on the data to form a single program unit called an object (IBO).
- A variable in which an object stores a value representing an aspect of the object’s state. Formally: an instance field.
- An example or single occurrence of something; ex: a serious instance of corruption; the search finds every instance where the word appears (Oxford University, 2013).
- 1: An object’s state has integrity when every one of the object’s fields contains a valid value.
- 2: A programmer’s solemn obligation is to ensure the integrity of an object’s state.
- A subprogram which performs a task (like a procedure) or returns a value (like a function). Instance methods are called against (invoked against) an instance of a class (an object). Static methods have no implicit parameters; that is to say, they are not called against an object.
- method signature
- The header of a method which specifies its access level, name, return type, and parameters (if any).
- Operator required for instantiation of a class. Requires a single postfix argument: a constructor call. Performs three actions: (1) allocates memory for a new object, (2) invokes the object constructor, (3) returns a reference to the allocated memory (Creating Objects, n.d.)
- “the reserved constant used in Java to represent a void reference— i.e.: a pointer to nothing” (Green, Roedy. null: Java Glossary. Retrieved 2013-09-25.).
- 1: An instance of a class created by the process of instantiation.
- 2: A specific set of data and the methods for their manipulation. Every object has knowing responsibilities and doing responsibilities.
- 3: A representation or model of an entity in the “real world.”
- When the same name is used for more than one method, the name is overloaded. This is particularly common for constructors, because all constructors must have the same name: the name of the class. Overloaded methods have the same name but different parameters: different in datatype and/or listed in different order (Horstmann, 2002).
- Operators can also be overloaded. For example: “+” means addition in one context, positive in another, and concatenation in yet another.
- The principle that the action of a method depends on the datatype of the object against which the method is invoked. For example, the same method may have a different action on an object of a subclass than on an object of the corresponding superclass. (See also Polymorphism.)
- In BlueJ, a directory which contains the files which comprise a Java program.
- The set of values stored in the fields of an object.
- 1: A method which does not act on an object; a static method; ex: method main does not act on any object.
- 2: A field which describes the state of a class, not of a particular object; a static field; ex:
static final int NEXT_ACCOUNT_NUMBER = 1;
- 3: A declared constant; ex:
static final int ADULT = 1; static final boolean TAXABLE = true;
- “The set of rules that defines the combinations of symbols that are considered to be a correctly structured document or fragment in [a programming] language.” (Syntax (programming languages), 2016).
- 1: A reference to the current object (Oracle. Using the this Keyword. Retrieved 2016-01-01).
- 2: A reference to the implicit parameter.
Creating Objects. (n.d.). Retrieved September 18, 2016, from https://docs.oracle.com/javase/tutorial/java/javaOO/objectcreation.html
Horstmann, C. (2002). Big Java. John Wiley & Sons, Inc. ISBN 0-471-40248-6.
Oxford University. (2013). New Oxford American Dictionary. NY: Oxford University Press [application].
Syntax (programming languages). (n.d.). In Wikipedia. Retrieved September 5, 2016, from https://en.wikipedia.org/wiki/Syntax_(programming_languages)
[This page last updated 2020-12-23 at 12h13 Toronto local time.]
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