Module 1 - Introduction to Java Flashcards
(124 cards)
1
Q
Is an object-oriented programming language developed by James Gosling and colleagues at Sun Microsystems in the early 1990s
A
Java
2
Q
Java is intended to be compiled to a _____, which is then run (generally using JIT compilation) by a Java Virtual Machine
A
Bytecode
3
Q
Who, where and when is Java developed?
A
James Gosling; Sun Microsystems; early 1990s
4
Q
Java was started as a project called _____ by James Gosling in _____.
A
Oak; June 1991
5
Q
The first public implementation in 1995
A
Java 1.0
6
Q
Java 1.0 made the promise of _____, with free runtimes on popular platform.
A
Write Once, Run Anywhere
7
Q
The major web browsers soon incorporated Java 1.0 into their standard configurations in a secure _____ configuration.
A
Applet
8
Q
New versions for large and small platforms (J2EE and J2ME) soon were designed with the advent of _____.
A
Java 2
9
Q
Sun has not announced any plans for a _____.
A
Java 3
10
Q
When was Sun reached out to the ISO/IEC JTCI and then Ecma International to formalize Java, but they quickly withdrew.
A
1997
11
Q
Java continues to be a _____ standard regulated by the _____.
A
de facto proprietary; Java Community Process
12
Q
With the revenue generated by new vision such as the _____, Sun made several Java implementations free of charge.
A
Java Enterprise Framework
13
Q
The critical difference is that the compiler is not present in the _____, which differentiates between its Software Development Kit (SDK) and JRE (JRE).
A
JRE
14
Q
When was Sun launched a considerable amount of Java in the GNU General Public License as free and open-source software (GPL).
A
November 13, 2006
15
Q
When was Sun completed the process by releasing a fully accessible, all free and open-source Java’s core code, except for a small portion of the code that Sun did not copyright.
A
May 8, 2007
16
Q
The 5 Primary Objectives of the Development of Java Language
A
- The object-oriented approach should be employed
- It should allow multiple operating systems to run the same program
- It should have built-in computer network support
- It should be configured to execute code from distant sources safely
- By selecting which parts of the other object-oriented languages are considered acceptable. It should be simple to use
17
Q
- Refers to a method of programming and language design
- Idea is to design software so that the various types of data it manipulates are combined together with their relevant operations
A
Object Orientation (OO)
18
Q
Data and code are combined into entities called _____
A
Objects
19
Q
An _____ can be thought of as self-contained bundle of _____ (code) and _____ (data).
A
object; behavior; state
20
Q
What is the principle of Object Orientation (OO)?
A
To make large software projects easier to manage, thus improving quality and reducing the number of failed projects
21
Q
Object Orientation develop more generic objects so that software can become more _____ between projects.
A
reusable
22
Q
Software objects can hopefully be seen more as _____ components, helping the software industry build projects largely from existing and well-tested pieces, thus leading to a massive reduction in development times.
A
pluggable
23
Q
Programs written in the Java language must run similarly on diverse hardware.
A
Platform Independence
24
Q
The code is run on a _____, a program written in native code on the host hardware that interprets and executes generic Java _____.
A
Virtual Machine (VM); bytecode
25
Java bytecode is interpreted or converted to native machine instructions by the _____.
JIT Compiler
26
In some languages the programmer allocates memory to create any object stored on the heap and is responsible for later manually deallocating that memory to delete any such objects.
Problem in Memory Management
27
The programmer determines when objects are created, and the Java runtime is responsible for managing the object's lifecycle.
Java Automatic Garbage Collection (Avoidance of the Problem)
28
What are the 7 Benefits of Java?
1. Java is used in networking
2. Java is dynamic
3. Java is reliable
4. Java is simple
5. Java is secure
6. Java is portable
7. Java is free
29
The Java language has many classes to facilitate Internet communications. Java classes can be loaded in most browsers to facilitate secure transactions over the Internet.
Java is used in networking
30
Java makes it possible to reuse previously written programs to lessen the workload of a programmer.
Java is dynamic
31
Java is _____ because it excludes some components that are error-prone. It also provides a way for programmers to anticipate and handle errors in their program.
Java is reliable
32
The Java programming language was designed to make OOP easier. Once you understand how components in a program are treated as objects, you will find Java fairly simple.
Java is simple
33
Java ensures that a program can go only where it was designed to go. It eliminates the possibility of altering system data unintentionally.
Java is secure
34
Java codes have the filename extension .java. When compiled, a class file with .class extension is created. This file can then run on any machine which has the Java Virtual Machine, thus, making it portable.
Java is portable
35
Java codes have the filename extension _____. When compiled, a class file with _____ extension is created. This file can then run on any machine which has the _____, thus, making it portable.
.java; .class; Java Virtual Machine
36
Java ensures that a program can go only where it was designed to go. It eliminates the possibility of altering system data unintentionally.
Java is free
37
- Bundles all the tools you need to write, debug, and test your code
- Allows developers to work in a single environment and improve their programming workflow
IDE or Integrated Development Environment
38
What are the 5 Essential Java IDE Tools?
1. Debugging
2. Syntax Highlighting
3. Build Automation
4. Code Completion
5. Graphical User Interface (GUI)
39
While debuggers vary among different IDEs, it’s important to have a tool to highlight potential errors and help you step through your code.
Debugging
40
Built-in highlighting is crucial for readability and efficiency. This tool can help you find errors in your code and allows you to sift through your code at a quicker speed.
Syntax Highlighting
41
A good IDE will allow you to write and run your Java code in the same window, increasing the productivity and efficiency of your program.
Build Automation
42
This tool identifies and inserts code components to save you time and lower the risk of typos and bugs.
Code Completion
43
Enables an intuitive programming interface
Graphical User Interface (GUI)
44
What are the 7 Popular Java IDEs?
1. Eclipse
2. NetBeans
3. IntelliJ IDEA
4. BlueJ
5. Oracle JDeveloper
6. MyEclipse
7. JCreator
45
It’s free, open-source, and has an extensive plugin ecosystem that allows users to customize functionalities for application development.
Eclipse
46
Is the official IDE for Java 8, making it a top Java IDE for creating
desktop, mobile, and web applications applications. It is open-source and is used to develop desktop, web, and mobile applications along with HTML5 and C++.
NetBeans
47
It’s a capable and ergonomic IDE, with features to boost productivity without cluttering the user interface. It includes a set of tools that make programming easier, like smart completion, cross-language refactoring, data flow analysis, and language injection.
IntelliJ IDEA
48
Two Editions of IntelliJ
1. Community Edition
| 2. Ultimate Edition
49
IntelliJ edition that is free and open-source, with a focus on Android and Java Virtual Machine (JVM) development.
Community Edition
50
IntelliJ edition that is paid, with a focus on web and enterprise development.
Ultimate Edition
51
Was originally created for educational content but is now used on a smaller scale for software development. While it is a great Java IDE for beginners, many Java veterans opt to use it because of its interactive and clutter-free user interface.
BlueJ
52
Is a freeware IDE offered by Oracle. It includes features for application development in Java, PHP, SQL, XML, HTML, and JavaScript. It covers the entire development lifecycle: coding, designing, debugging, optimizing, profiling, and deploying.
Oracle JDeveloper
53
Is a proprietary Java IDE that is built upon the Eclipse platform. It uses both proprietary and open-source code in the development environment, and its tools can be used for Java application development and web development. It offers support for Angular, HTML, TypeScript, and JavaScript.
MyEclipse
54
Is a powerful and lightweight Java IDE written in C++, which makes it faster than other Java IDEs. It has an interface similar to that of Microsoft’s Visual Studio making source code navigation easier. It can handle various JDK profiles for multiple projects and offers strong API guidelines for developers. It’s a great option for beginners because of its intuitive user interface.
JCreator
55
Use case: You’re a multi-language developer looking for an IDE that offers an extensive plugin environment and don’t mind taking the time to customize your experience.
Eclipse
56
Cross-platform: Windows, Mac OS, Linux, Solaris.
Eclipse, NetBeans
57
Use case: You’re a multi-language developer looking for a ready-to-go IDE with developer collaboration tools and Maven support.
NetBeans
58
Cross-platform: Linux, Mac OS, Windows, Solaris
NetBeans
59
Use case: You’re a developer whose company will pay for an IDE and who’s looking for an intuitive IDE that’s easy to use out of the box. You also have a fast computer that can handle a heavier IDE.
IntelliJ IDEA
60
Cross-platform: Linux, Mac OS, Windows
IntelliJ IDEA
61
Use case: You’re newer to Java development and want more practice creating simple projects in an intuitive, lightweight environment
BlueJ
62
Cross-platform: Windows, Linux, Mac OS.
BlueJ
63
Use case: You’re an experienced Java developer looking for a wide set of tools and have a computer that can run a heavy program.
Oracle JDeveloper
64
Cross-platform: Windows, Linux, Mac OS
Oracle JDeveloper
65
Use case: You’re familiar with Eclipse, and your company will pay for an IDE. You also have a fast computer to handle a heavy IDE.
MyEclipse
66
Cross-platform: Linux, Mac OS, Windows
MyEclipse, IntelliJ IDEA, BlueJ, Oracle JDeveloper,
67
Use case: You’re a Windows user who’s looking for a fast IDE with a clean interface and you’re willing to pay for it.
JCreator
68
Not cross-platform: Windows
JCreator
69
Was conceived to model real world objects
Object-Oriented Programming (OOP)
70
In OOP, a _____ defines the _____ and _____ of a set of _____. An _____ is an instance of a _____.
class; common variables (attributes); methods (functions); objects; object; class
71
Is a blueprint or prototype from which objects are created
Class
72
Java _____ keyword is an access modifier. The access modifier is accessible everywhere. So, we can easily access it inside and outside the class and package.
public
73
Every line of code that runs in Java must be inside a _____
class
74
A class should always start with an _____
Uppercase First Letter
75
The _____ must match the _____.
Name of the Java File; Class Name
76
Indicates the start of a block
Curly Brace ({)
77
What is the symbol for Multiple Line Comments?
Starts with /* and ends with */
78
- Is something used to document a part of a code
- It is not part of the program itself, but used for documentation purposes.
- It is a good programming practice to add it to your code
- Ignored and NOT executed by the program.
Comment
79
Indicates the name of one method in Hello class which is the main method
public static void main(String[] args) {
80
Is the starting point of a Java program
Main Method
81
All programs except _____ written in Java start with the main method
Applets
82
Is used for single line comment
Two Backslash Character (//)
83
Is used to display messages to the command window
System.out.println
84
The last two lines which contains the _____ is used to close the main method and class respectively.
Two Curly Braces
} //end of main
} // end of class
85
Is used to declare a class in Java
class keyword
86
Is an access modifier that represents visibility. It means it is visible to all.
public keyword
87
If we declare any method as _____, it is known as the _____. The core advantage of the (2nd answer) is that there is no need to create an object to invoke the (2nd answer).
static keyword; static method
88
Is executed by the JVM, so it doesn't require creating an object to invoke it. So, it saves memory.
main() method
89
Is the return type of the method. It means it doesn't return any value.
void
90
Represents the starting point of the program.
main
91
Is used for command line argument.
String[] args or String args[]
92
Is used to print statement.
System.out.println()
93
System is a _____, out is an _____ of the PrintStream class, _____ is a method of the PrintStream class.
class; object; println()
94
Errors are usually typing errors
Syntax Errors Syntax
95
– Misspelled a command in Java
| – Forgot to write a semi-colon at the end of a statement
Common Syntax Errors
96
Compiler Error Message: class PrinHello is public, should be declared in a file named PrintHello.java
Solution: check the filename with the class name class PrinHello vs. PrintHello.java
Change the class name to match the File name.
97
Compiler Error Message: reached end of file while parsing
Solution: check the delimiter { } pairing.
Ensure that each { is paired with }
98
Compiler Error Message: cannot find symbol class string
Solution: Change string to String, it might be that string is in lower case.
99
Compiler Error Message: package system does not exist
Solution: system should be in Upper case. Change to System.
100
Compiler Error Message: cannot find symbol method printIn(java.lang.String)
Solution: Change printIn to println; its print LN NOT print IN
101
Compiler Error Message: unclosed string literal
Solution: check if the " has a pair.
102
Compiler Error Message: ';' expected
Solution: place a ; at the end of the statement
103
Errors that will not display until you run or execute your program
Runtime Errors
104
Your Java programs should always end with the _____
.java extension
105
Filenames should match the name of your _____.
public class
106
You should write _____ in your code explaining what a certain class does, or what a certain method does.
Comments
107
– These are notes written to a code for documentation purposes.
– Those texts are not part of the program and does not affect the flow of the program.
Java Comments
108
- // symbol denotes a single line.
| - Comments is written per line
Single Line Comment
109
You can also create _____ by starting the line with /* and ending it with */ .
Multiple Line Comments
110
What programming language was Java’s successor?
C/C++ Programming
111
Who is the Author of Java language?
James Gosling
112
What is the original name of Java language?
Oak
113
What type of Java program can be run inside a Java supported Web browser?
Applet
114
Which company owns Java at present?
Oracle
115
What software runs a Java program in a computer?
Java Runtime Environment (JRE)
116
What is the output file of a Java compiled program?
.class file
117
When was the first version of Java (i.e. Java 1.0) release?
1995
118
What type of programming language is Java?
Object-Oriented Programming
119
What does JIT in Java means?
Just-In-Time
120
What is the correct header line for Java program?
public static void main(String[] args) {
or
public static void main(String args[]) {
121
What does a single line comment look like in Java?
//comment
122
Program statements in Java must end with
semi colon (;)
123
What is an example of multi-line comment?
```
/* The beginning of a multi-line
the end of the multi-line */
```
124
What do you call the curly braces found at the starting of the program and end of the program?
Delimiter
