University Of Arizona: Ece 373: Intro To Java

Front 1

Objects consist of

Back 1

Attributes and methods

Front 2

Objects represent

Back 2

State: Value of all attributes

Behavior: What actions it can perform, defined by methods.

Front 3

A Class is composed of

Back 3

A name, attributes, and operations

Front 4

If there is more then one Class in a file then...

Back 4

only one can be public and it must match the name of the file.

Front 5

The Job of a constructor is?

Back 5

allocate memory and initialize fields of a new object.

Front 6

what do Accessors and mutators do?

Back 6

Get and set fields of an object

Front 7

Encapsulation

Back 7

Enclosing the proper attributes and method in a single class

Front 8

in UML diagrams variable types are placed...

Back 8

after the variable name.

Front 9

in UML diagrams return types are placed...

Back 9

after the method name. while variables are placed inside.

Front 10

The class that starts the application must have?

Back 10

A main method. Can be used as a driver.

Front 11

A driver program does what?

Back 11

Tests or runs the application. Makes all the classes interact as needed.

Front 12

To read input from a keyboard

Back 12

We use the scanner class.

import java.util.Scanner;

Front 13

To use a scanner...

Back 13

Double payRate;
Scanner keyboard = new Scanner(System.in);

System.out.print("What is your hourly pay rate? ");
payRate = keyboard.nextDouble();

Front 14

an instance field is?

Back 14

A variable created in the class but not in a method.

Front 15

The keyword final creates?

Back 15

Constant variables

Front 16

Constructors have what special properties

Back 16

-Same name as class

-No return type(not even void)

-typically public

Front 17

Default constructor does what?

Back 17

-Sets numeric fields to 0

-sets boolean fields to false

-sets reference variables to null

Front 18

Can a constructor use this in a constructor to call another constructor

Back 18

yes. Must be first statement in the constructor.

Front 19

An enhanced for loop has the form...

Back 19

int[] numbers = {3, 6, 9};
For(int val : numbers)
{
System.out.println("The next value is" + val);
}

Front 20

What needs to happen to an array of objects?

Back 20

Each needs to be intialized

Front 21

ragged array?

Back 21

When rows of a 2D array are of different lengths

Front 22

An array list has a default capacity of?

Back 22

10

Front 23

to open a file for output...

Back 23

create an instance of PrintWriter class.

PrintWriter outputFile =

new PrintWriter("StudentData.txt");

Front 24

To append text to a file...

Back 24

create a FileWriter class. then create PrintWriter

PrintWriter outputFile =

new PrintWriter("StudentData.txt");

PrintWriter outputFile = new PrintWriter(fw);

Front 25

To read data from a file you use?

Back 25

File class and the Scanner class.

File myFile = new File("Customers.txt");
Scanner inputFile = new Scanner(myFile);

Front 26

Wrapper classes are provided for?

Back 26

All primitive data types: byte, double, float, int, long, and short.

Front 27

what is Autoboxing and Unboxing?

Back 27

declaring a wrapper class variable and assigning a value or vice versa.

Front 28

Wrapper classes are?

Back 28

Immutable and thus once the object is created it cannot be changed.

Front 29

A StringBuilder class allows?

Back 29

the contents to be changed: change specific char, insert char, etc

Front 30

A StringTokenizer does what?

Back 30

breaks a string down into parts or tokens.

Front 31

Tokens are?

Back 31

a series of words or other items of data separated by spaces or other characters(delimiter). Example-date:
"11-22-2007"

Front 32

the String class has a method split that?

Back 32

Tokenizes a String and returns an array of String objects.