Week 1 Flashcards
Infrastructure as a Service (IaaS)
a self-service model for managing remote data center infrastructures.
Platform as a Service (PaaS)
allows organizations to build, run and manage applications without the IT infrastructure. This makes it easier and faster to develop, test and deploy applications.
Software as a Service (SaaS)
replaces the traditional on-device software with software that is licensed on a subscription basis. It is centrally hosted in the cloud. A good example is Salesforce.com.
AWS Region Define.
a geographical location with a collection of availability zones mapped to physical data centers in that region.
AWS Availability Zone
a logical data center in a region available for use by any AWS customer.
AMI (Amazon Machine Image)
provides the information required to launch an instance. Think of it as a template for an EC2 Instance.
Security groups
a virtual firewall for your EC2 instances to control incoming and outgoing traffic based on their IP address.
___________ rules enable you to filter traffic based on protocols and port numbers.
Security group
Amazon Elastic Compute Cloud (Amazon EC2)
a web service that provides secure, resizable compute capacity in the cloud.
The “Elastic” nature of the service allows developers to
instantly scale to meet spikes in traffic or demand.
a virtual server in the cloud.
An Instance
What is Java? Why Java?
Java is a high-level OOP language with rich API Libraries.
Write once run anywhere, static types, compiled languages.
What is JRE?
Java runtime environment. contains JVM.
What is JVM?
Java virtual machine. Runs compiled JAva code.
What is JDK?
Java developer kit. Has a compiler. debugger. Contains JRE and JVM.
What is an object/class?
Class is a blueprint for an object.
What is the root class from which every class extends?
The ‘Object’ Class… (This is a class called object.)
What are the primitive data types in Java?
boolean.
byte.
short.
int.
long.
float.
double.
char.
Where are the strings stored?
In the string pool in the heap?
What is a heap in Java?
a chunk of memory which is shared among all threads.
What is an immutable object?
An object whose internal state remains constant after it has been entirely created.
What are the benefits of keeping String immutable in java?
caching, security, synchronization, and performance.
In this heap type, the root node is greater than it’s children.
Max-Heap.
In this heap type, the root node is the smallest among all the other keys present in the heap.
Min-heap.
Does stack memory use LIFO or FIFO structure?
LIFO
A part of computer’s memory where temporary variables, which are created by all functions you do, are stored.
Java Stack Memory.
A block of code which only runs when it is called.
method.
What is the difference between…
public static int x = 4;
public int y = 2;
In the first declaration, the variable x = 4 will carry till the end of the program.
In the second declaration, the variable will not exist at the end of the current function. It is a local variable.
What data types are supported in switch statements?
String.
int.
char.
short.
byte.
enums.
How to pass multiple values with a single parameter into a method?
Use varargs.
Vararg.
a method that takes a variable number of arguments.
Where in Java memory are objects stored?
The Heap.
What methods are available in the object class?
.clone
.hashcode
.equals
.toString
what does ‘==’ mean?
tests to see if two reference variables refer to the exact same instance of an object.
what does ‘.equals()’ do?
tests to see if two objects being compared to each other are equivalent. (does not have to be the exact same instance of an object)
What are the 4 pillars of OOP?
Abstraction.
Polymorphism.
Inheritance.
Encapsulation.
What is abstraction?
Hiding implementation details through a higher-level construct, thereby decreasing coupling and increasing cohesion.
What is polymorphism?
allowing the implementation of a behavior to vary, whether between subclasses or within the same class.
What is ‘super()’ used for?
to invoke immediate parent class constructor.
What is inheritance?
Receiving state and behavior from other classes, thereby reducing boiler plate and duplicate code and allowing for hierarchies of classes.
What is encapulation?
Restricting access to data members by using access modifier and getter/setter methods.
Bash is a ____ that interprets ____ commands like “ls” that interact with the ___.
shell; linux; filesystem.
How do you compile java code contained in the file helloWorld.java and then run it on the command line?
javac HelloWorld.java, then java HelloWorld
Method Overriding is…
Same method signature but different implementation.
keyword to show inheritance in java?
extends.
Static methods can be called without instantiating the class first. T/F?
True.
The main() method must be static, in order to be executed by the JVM. T/F?
True.
A final class can not be instantiated. T/F?
False.
A final class can be instantiated. T/F?
True.
The keyword super() calls the constructor of the….
parent class.
the keyword static means…
something belongs to the class and is globally available to all instances.
Access modifier public define.
can be accessed anywhere in the program.
Access modifier private define.
can only be accessed within the same class.
Access modifier default define.
can only be accessed from within the same package.
Access modifier protected define.
can be accessed within the same package or through inheritance by subclasses.
Java supports multiple inheritances of classes. T/F?
False.
What is the purpose of the java compiler?
to transfer java code into instructions usable by the JVM.
What is the purpose of the java compiler?
to transfer java code into instructions usable by the JVM.
Both String and StringBuffer are mutable. T/F?
False.
What is git?
A version control tool.
How do you create a new branch in git?
git checkout -b
By default, in a git repository, origin refers to:
The remote repository that the local repository was cloned from.
What is the correct series of commands to:
1) Go to the “main” branch
2) See the current state of the files in the branch
3) Make a change
4) Update the remote repository
git checkout main;
git status;
git commit;
git push;
git checkout main;
Got to the “main” branch.
git status;
See the current state of the files in the branch.
git commit;
Make a change.
git push;
update the remote repository.
A final class can be extended. T/F?
False.
Can I take a variable of larger size than another and reassign without casting?
No.
.equals()
tests to see if the two objects being compared to each other are equivalent.
things that make git unique.
allows tracking changes, view past changes, revert to old versions.
add many different codebase locations and keep them in sync.
tracks units of work in “commits” that are linked to each other.
How would you prevent a file from being tracked by git?
Add the file path to a file called .gitignore
What is a branch?
a separate path of changes made to the codebase.
How to create a new branch?
git checkout -b mynewbranch
What is a merge conflict?
When two changes in git attempt to merge and have different code in them.
How do you resolve a merge conflict?
Go to the file with the conflict. Remove the special markings that designate the merge conflict and select the code to keep.
What is a github pull request?
a request to merge changes made in the code from one branch into another.
command to pull any updates from central repo
git pull
command to stage changes
git add
command to make a commit
git commit -m my commit message
command to push to the central repo
git push
how would you go back in your commit history if you make a mistake?
git checkout
What is the git workflow for editing code and saving changes?
Pull any updates from central repo.
Make changes to codebase.
Stage the changes.
Make a commit.
Push to the central repo.
a self-service model for managing remote data center infrastructures.
Infrastructure as a Service (IaaS)
Reverse
allows organizations to build, run and manage applications without the IT infrastructure. This makes it easier and faster to develop, test and deploy applications.
Platform as a Service (PaaS)
Reverse
replaces the traditional on-device software with software that is licensed on a subscription basis. It is centrally hosted in the cloud. A good example is Salesforce.com.
Software as a Service (SaaS)
Reverse
a geographical location with a collection of availability zones mapped to physical data centers in that region.
AWS Region Define.
Reverse
a logical data center in a region available for use by any AWS customer.
AWS Availability Zone
Reverse
provides the information required to launch an instance. Think of it as a template for an EC2 Instance.
AMI (Amazon Machine Image)
Reverse
a virtual firewall for your EC2 instances to control incoming and outgoing traffic based on their IP address.
Security groups
Reverse
Security group
___________ rules enable you to filter traffic based on protocols and port numbers.
Reverse
a web service that provides secure, resizable compute capacity in the cloud.
Amazon Elastic Compute Cloud (Amazon EC2)
Reverse
instantly scale to meet spikes in traffic or demand.
The “Elastic” nature of the service allows developers to
Reverse
An Instance
a virtual server in the cloud.
Reverse
Java is a high-level OOP language with rich API Libraries.
Write once run anywhere, static types, compiled languages.
What is Java? Why Java?
Reverse
Java runtime environment. contains JVM.
What is JRE?
Reverse
Java virtual machine. Runs compiled JAva code.
What is JVM?
Reverse
Java developer kit. Has a compiler. debugger. Contains JRE and JVM.
What is JDK?
Reverse
Class is a blueprint for an object.
What is an object/class?
Reverse
The ‘Object’ Class… (This is a class called object.)
What is the root class from which every class extends?
Reverse
boolean.
byte.
short.
int.
long.
float.
double.
char.
What are the primitive data types in Java?
Reverse
In the string pool in the heap?
Where are the strings stored?
Reverse
a chunk of memory which is shared among all threads.
What is a heap in Java?
Reverse
An object whose internal state remains constant after it has been entirely created.
What is an immutable object?
Reverse
caching, security, synchronization, and performance.
What are the benefits of keeping String immutable in java?
Reverse
Max-Heap.
In this heap type, the root node is greater than it’s children.
Reverse
Min-heap.
In this heap type, the root node is the smallest among all the other keys present in the heap.
Reverse
LIFO
Does stack memory use LIFO or FIFO structure?
Reverse
Java Stack Memory.
A part of computer’s memory where temporary variables, which are created by all functions you do, are stored.
Reverse
method.
A block of code which only runs when it is called.
Reverse
In the first declaration, the variable x = 4 will carry till the end of the program.
In the second declaration, the variable will not exist at the end of the current function. It is a local variable.
What is the difference between…
public static int x = 4;
public int y = 2;
Reverse
String.
int.
char.
short.
byte.
enums.
What data types are supported in switch statements?
Reverse
Use varargs.
How to pass multiple values with a single parameter into a method?
Reverse
a method that takes a variable number of arguments.
Vararg.
Reverse
The Heap.
Where in Java memory are objects stored?
Reverse
.clone
.hashcode
.equals
.toString
What methods are available in the object class?
Reverse
tests to see if two reference variables refer to the exact same instance of an object.
what does ‘==’ mean?
Reverse
tests to see if two objects being compared to each other are equivalent. (does not have to be the exact same instance of an object)
what does ‘.equals()’ do?
Reverse
Abstraction.
Polymorphism.
Inheritance.
Encapsulation.
What are the 4 pillars of OOP?
Reverse
Hiding implementation details through a higher-level construct, thereby decreasing coupling and increasing cohesion.
What is abstraction?
Reverse
allowing the implementation of a behavior to vary, whether between subclasses or within the same class.
What is polymorphism?
Reverse
to invoke immediate parent class constructor.
What is ‘super()’ used for?
Reverse
Receiving state and behavior from other classes, thereby reducing boiler plate and duplicate code and allowing for hierarchies of classes.
What is inheritance?
Reverse
Restricting access to data members by using access modifier and getter/setter methods.
What is encapulation?
Reverse
shell; linux; filesystem.
Bash is a ____ that interprets ____ commands like “ls” that interact with the ___.
Reverse
javac HelloWorld.java, then java HelloWorld
How do you compile java code contained in the file helloWorld.java and then run it on the command line?
Reverse
Same method signature but different implementation.
Method Overriding is…
Reverse
extends.
keyword to show inheritance in java?
Reverse
True.
Static methods can be called without instantiating the class first. T/F?
Reverse
True.
The main() method must be static, in order to be executed by the JVM. T/F?
Reverse
False.
A final class can not be instantiated. T/F?
Reverse
True.
A final class can be instantiated. T/F?
Reverse
parent class.
The keyword super() calls the constructor of the….
Reverse
something belongs to the class and is globally available to all instances.
the keyword static means…
Reverse
can be accessed anywhere in the program.
Access modifier public define.
Reverse
can only be accessed within the same class.
Access modifier private define.
Reverse
can only be accessed from within the same package.
Access modifier default define.
Reverse
can be accessed within the same package or through inheritance by subclasses.
Access modifier protected define.
Reverse
False.
Java supports multiple inheritances of classes. T/F?
Reverse
to transfer java code into instructions usable by the JVM.
What is the purpose of the java compiler?
Reverse
to transfer java code into instructions usable by the JVM.
What is the purpose of the java compiler?
Reverse
False.
Both String and StringBuffer are mutable. T/F?
Reverse
A version control tool.
What is git?
Reverse
git checkout -b
How do you create a new branch in git?
Reverse
The remote repository that the local repository was cloned from.
By default, in a git repository, origin refers to:
Reverse
git checkout main;
git status;
git commit;
git push;
What is the correct series of commands to:
1) Go to the “main” branch
2) See the current state of the files in the branch
3) Make a change
4) Update the remote repository
Reverse
Got to the “main” branch.
git checkout main;
Reverse
See the current state of the files in the branch.
git status;
Reverse
Make a change.
git commit;
Reverse
update the remote repository.
git push;
Reverse
False.
A final class can be extended. T/F?
Reverse
No.
Can I take a variable of larger size than another and reassign without casting?
Reverse
tests to see if the two objects being compared to each other are equivalent.
.equals()
Reverse
allows tracking changes, view past changes, revert to old versions.
add many different codebase locations and keep them in sync.
tracks units of work in “commits” that are linked to each other.
things that make git unique.
Reverse
Add the file path to a file called .gitignore
How would you prevent a file from being tracked by git?
Reverse
a separate path of changes made to the codebase.
What is a branch?
Reverse
git checkout -b mynewbranch
How to create a new branch?
Reverse
When two changes in git attempt to merge and have different code in them.
What is a merge conflict?
Reverse
Go to the file with the conflict. Remove the special markings that designate the merge conflict and select the code to keep.
How do you resolve a merge conflict?
Reverse
a request to merge changes made in the code from one branch into another.
What is a github pull request?
Reverse
git pull
command to pull any updates from central repo
Reverse
git add
command to stage changes
Reverse
git commit -m my commit message
command to make a commit
Reverse
git push
command to push to the central repo
Reverse
git checkout
how would you go back in your commit history if you make a mistake?
Reverse
Pull any updates from central repo.
Make changes to codebase.
Stage the changes.
Make a commit.
Push to the central repo.
What is the git workflow for editing code and saving changes?
