OCA Summary 1 pag 40

Question 1

Java classes consist of members called ___ and ___.

Answer 1

fileds and methods

Question 2

An ___ is an instance of a Java class

Answer 2

object

Question 3

There are three styles of comments:

Answer 3

single-line comment
multiline comment
Javadoc comment

Question 4

Java beings program execution with a ____ method

Answer 4

main()

Question 5

The most common signature for the main() method run from the command line is:

Answer 5

public static void main(String[] args)

Question 6

Arguments are passed in after the ___ ___

Answer 6

class name

Question 7

Arguments are indexed starting with ___

Answer 7

0

Question 8

Java code is organized into folders called ____

Answer 8

packages

Question 9

To reference classes in other packages, you use an ___ ____.

Answer 9

import statement

Question 10

A wildcard ending an import statement means you want to import all ___ in that ____

Answer 10

classes

package

Question 11

What is the special package that does not need to be imported?

Answer 11

java.lang

Question 12

Constructors create Java ____

Answer 12

objects

Question 13

A constructor is a method matching the ___ ___ and omitting the ___ ___

Answer 13

class name
return type

Question 14

When an object is instantiated, ___ and ____ of code are initialized first. Then the ___ is run.

Answer 14

fields and block of code

constructor

Question 15

____ ____ are the basic building blocks of Java types. They are assembled into reference types.

Answer 15

Primitive types

Question 16

Reference types can have methods and be assigned to ___

Answer 16

null

Question 17

In addition “normal” numbers, ____ ____ are allowed to begin with 0 (___), 0x (__), 0X (___), 0b (___) or 0B (__).

Answer 17

numeric literals
octal
hex
binary

Question 18

Numeric literals are also allowed to contain ___ as long as they are directly between two other ___

Answer 18

underscores

numbers

Question 19

Declaring a variable involves starting the ___ ___ and giving the variable a ___.

Answer 19

data type

name

Question 20

Variables that represent fields in a class are automatically initialized to their corresponding “___” or __ value during instantiation.

Answer 20

zero

null

Question 21

___ variables must be specifically initialized.

Answer 21

Local

Question 22

Identifiers may contain ___, ___, __, or __.

Answer 22

letters
numbers
$ (dollar sign)
_ (underscore)

Question 23

Identifiers may not begin with ___

Answer 23

numbers

Question 24

Scope refers to that portion of code where a variable can be ___

Answer 24

accessed

Question 25

There are three kinds of variables in Java, depending on their scope:

Answer 25

``` Instance variables class variables local variables ```

Question 26

___ variables are the nonstatic fields of your class

Answer 26

Instance variables

Question 27

Instance variables are the non____ fields of your class

Answer 27

static

Question 28

___ variables are the static fields within a class

Answer 28

class variables

Question 29

___ variables are declared within a method

Answer 29

local variables

Question 30

For some class elements, ___ matters within the file

Answer 30

order

Question 31

T or F | The package statement comes first if present.

Answer 31

true | imports

Question 32

Name the order in which class elements need to be: methods import statement fields package statement

Answer 32

package statement imports fileds and methods are allowed to be in any order within the class

Question 33

___ ___ is responsible for removing objects from memory when they can never be used again.

Answer 33

Garbage Collection

Question 34

An object becomes eligible for garbage collection when there are no more ___ to it or its ____ have all gone out of scope

Answer 34

references

Question 35

The finalize() method will run ___ for each object if/when it is first garbage collected.

Answer 35

once

Question 36

Java code is object oriented, meaning all ___ is ___ in ___.

Answer 36

All Code is Defined in Classes

Question 37

____ ____ allow classes to encapsulate data.

Answer 37

Access modifiers

Question 38

Access modifiers allow classes to ___ ___.

Answer 38

encapsulate data

Question 39

Java is platform independent, ___ to bytecode

Answer 39

compiling

Question 40

Java is platform independent, compiling to ___

Answer 40

bytecode

Question 41

Java is robust and simple by not providing ___ or operator ___.

Answer 41

pointers | operator overloading

Question 42

Java is secure because it runs inside a ____ ____

Answer 42

virtual machine