Java Final!!!!!!

Front 1

What must you do to instantiate writing to a file object?

Back 1

PrintWriter writer = new PrintWriter(new FileWriter("outfile.txt"));

Front 2

What must you do after writing to a file?

Back 2

writer.close();

Front 3

How must you declare that you might get an error related to reading and writing from files?

Back 3

throws IOException in method heading

Front 4

What must your code look like to read from a file?

Back 4

Scanner filescan = new Scanner(new FileReader('infile.txt"));

Front 5

How must you instantiate a Random object?

Back 5

Random random = new Random();

Front 6

What is the javadoc format?

Back 6

/**
Description
@param
@return
*/

Front 7

What happens when a primitive variable is passed to a method?

Back 7

CANNOT CHANGE THE CORRESPONDING VARIABLE IN MAIN FROM WITHIN THE METHOD

Front 8

What happens when an object reference is passed to a method?

Back 8

-parameter variable points to the original object
-changes made in the method are permanent

Front 9

Instance methods are called with ______

Back 9

class object and may interact directly on instance data methods

Front 10

Static methods are called with ______

Back 10

the class name (does not need any instance methods to do its job because it is stand alone)

Front 11

The reference variable holds the ______, whereas the object holds ______

Back 11

memory location of the object; the actual data

Front 12

What methods does the Object class in Java contain?

Back 12

clone ()
toString ()
equals()

Front 13

Array indices must start at __

Back 13

0

Front 14

We must declare a ___ to create

Back 14

size capacity

Front 15

______ tells us the declared size of an array

Back 15

.length

Front 16

How do you declare an array of ints carrying 20?

Back 16

int ra = new int[20];

Front 17

How do you access first index and set it to 23?

Back 17

ra[0] = 23;

Front 18

How do you initialize an array in one line?

Back 18

int hw[] = {45, 65, 32}

Front 19

int [][] ra (which one is columns and which rows?

Back 19

first is rows
second is columns

Front 20

What does .length mean for two dimensional arrays?

Back 20

number of rows

Front 21

How efficient are the various sorting methods?

Back 21

Bubble sort: n^2
selection sort: n^2
merge sort: n log n

Front 22

How efficient are the searching methods?

Back 22

Binary search: log n
linear search: n

Front 23

What is method overloading?

Back 23

Same name. different parameters

Front 24

What is method overriding?

Back 24

Same name, Same parameters

Front 25

What does extends mean?

Back 25

subclass extends base class

Front 26

What does super mean?

Back 26

to call base class constructor or over-ridden method in base class

Front 27

What does instanceof mean?

Back 27

to see if an object belongs to a specific class

Front 28

What does protected mean?

Back 28

to give access to derived classes

Front 29

What does implements mean?

Back 29

to say a class will have a method definitions to support an interface

Front 30

What is the method that is in the Comparable class?

Back 30

int compareTo(Object o)
returns negative int if < param, positive int if > param, 0 if the same

Front 31

How should you display error messages?

Back 31

System.err.print()

Front 32

If operation throws an exception that is not caught, what will happen?

Back 32

program will stop and printStackTrace

Front 33

What are unchecked Exception classes?

Back 33

RuntimeException
NullPointerException
InputMismatchException