Chapter 1 Flashcards
Objects
- Created from classes
- represent “things” from the real world or from some problem domain
- represents individual instances of the class
- ie. if class is car, objects are racecar, limousine etc
Classes
- represents all objects of a kind
- uppercase
- ie. car
Instance
- a particular object
- refer to objects as instances when we want to emphasize that they are of a particular class
- ie. the object is an instance of the class car
Objects naming convention
Lowercase
Objects have___ which can be invoked, and called what in Java?
-operations
-methods
What do methods have to pass additional info needed to execute?
parameters
Data type
specifies what kind of data can be passed to the parameter
-integer (int) specifies whole numbers
An object has attributes which are?
Values stored in fields
The class defines_________ but each object_________
-what fields an object has
-stores its own set of values (the state of the object)
State
-The set of values of all attributes defining an object
-inspect in java
Each class has a source code ___________________
-(java code) associated with it that defines its details (fields and methods)
Compilation
-java is a high level language
-but computers can only interpret low level machine code
-compilers translate programming code into machine code
What return type returns a value?
non-void return type
Signature
-The method name and the parameter types of a method
-it provides the info needed to invoke the method
ie.
void moveHorizontal (int distance)
signature = moveHorizontal(int)
Header
-provides info about the method in question
ie.
void moveHorizontal (int distance)
String type
indicates that a section of text (a word or sentence) is expected.
-always enclosed W/I double quotes.
Multiple instances
Many similar objects can be created from a single class
Fields
Object attributes, when some methods are called the state of the object or attributes changes.
ie. moveLeft changes the xPosition attribute
Boolean
A type that can represent 2 values: true or false
Result
Methods may return info about an object via a return value.
String getName()
string is the return type
Which return type doesn’t return a value
void as in:
void changeName (String replacementName)
What happens when you specify a color that is not known in Java?
it turns black
What happens when you enter a string without the quotes in Java?
Causes an error
ie:
(yellow is entered)
Error: cannot find symbol - variable yellow
Method calling
Objects can communicate by calling each other’s methods
Which are considered programming paradigms?
1. Java programming
2. Python programming
3. Object oriented programming
4. Event driven programming
5. Procedural programming
6. Pseudo programming
7. Assembly programming
8. Constructal programming
9. Artificial intelligence programming
10. Functional programming
OOP
Procedural
Assembly
Functional
Java is best know for supporting which programming paradigm?
OOP
T or F: Java objects model objects from a problem domain
True
