exam 1 (includes testing)

Question 1

open/closed principle

Answer 1

classes + libraries should be open for extensions but closed for modifications

Question 2

single-responsibility principle

Answer 2

a class should only have a single responsibility; only one factor should change how the class functions

Question 3

Liskov principle

Answer 3

subclasses should be uszable anywhere the superclass is expected without breaking the program

Question 4

interface segregation principle

Answer 4

many client-specific interfaces are better than one general purpose interface;

Question 5

dependency inversion principle

Answer 5

high-level modules should not depend on low-level modules; both should depend on abstractions; abstractions should not depend on concrete implementations, but concrete implementations should depend on abstraction

Question 6

SOLID

Answer 6

single-responsibility; open-closed; liskov; interface segregation; dependency inversion

Question 7

Java bytecode

Answer 7

.class files are filled with bytecode– binary– so it can be run on the JVM;

Question 8

package

Answer 8

organize code by grouping related classes; similar to a folder

Question 9

inheritance

Answer 9

a child class inherits methods and other features from a parent class; class Subclass extends Class

Question 10

project management

Question 11

HTTP

Answer 11

HyperText Transfer Protocol; request-response protocol where text has interconnected content; transfer information between networked devices

Question 12

HTTP has no state

Answer 12

each indication of something doesn’t depend on a past result;
ex: logging in only relies on the current request for a password. you log in if it’s correct, even if the previous one was wrong

Question 13

interface

Answer 13

build a class without concrete definition; “empty” methods

Question 14

implementation w inheritance

Answer 14

class className implements inter1, inter2 {
class className extends onlyOneSuperclass {

Question 15

@Override

Answer 15

use before an inherited method to change its behavior / modify for this class

Question 16

annotations

Answer 16

usually for the purpose of the reader/programmer; JUnit relies on annotations (@Test) but little else does

Question 17

@Test

Answer 17

tells JUnit where unit tests are located to run them

Question 18

JUnit

Answer 18

automated testing framework for Java

Question 19

JVM

Answer 19

engine that runs Java programs; takes .class files and bytecode and executes them

Question 20

javac

Answer 20

java compiler; turns .java into .class to be run by the java virtual machine

Question 21

a class may implement many/one:

Answer 21

many interfaces, but only extend one superclass