In this bonus lesson, we continue with the Java Foundations Tutorial. That is the thirteenth part of this series, and if you want to see the complete list of lessons, you can do it here.

We cannot start explaining the difference between JRE and JDK without also explaining JVM. JVM or Java Virtual Machine simply helps to execute programs on our devices. It provides an environment to run the programs. JVM requires libraries and files for code execution, and these files are presented in JRE. We can have different JRE versions for different platforms. They are all platform-dependent.

JRE = set of libraries + JVM

JDK or Java Development Kit is a full-featured development kit. It has all development tool that we might require for creating java programs. JDK contains the following tools:

1. Java Runtime Environment (JRE)
2. Interpreter
3. Compiler (javac)
4. Archiver (jar)
5. Documentation generator (javadoc)

If you want to run your program you will need to use java or javac commands. The javac command is used to compile Java programs, it takes .java file as input and produces bytecode. On the other hand, the java command is used to execute the bytecode of java. It takes byte code as input and runs it and produces the output.

In conclusion, if you want to run the java or JVM-based code, then JRE is required. But if you want to develop Java and JVM-based programs, then JDK is required. Depending on your needs you will use javac and java commands.

In the current lesson, we take a closer look at the most frequently used Java API classes. Svetlin Nakov will explain all about the Math class, how to generate random numbers, the need for BigInteger and BigDecimal in programming, and how to work with date and time in Java. We will also look at two of the main Java classes – Arrays and Formatter.

The Math class contains methods for performing basic numeric operations, such as round, min, max, abs, ceil, etc.. The Arrays class contains various methods which facilitate array manipulation. String.format() allows us to return the formatted string by given locale, format, and arguments.

In this lesson you will find many helpful examples and exercises, so make sure to practice what you’ve learned! That’s the only way to grasp the concept at hand.

BigInteger and BigDecimal are used for handling large and small numbers with great precision. BigInteger will throw an exception when the result is out of range. BigDecimal gives the user complete control over the rounding behavior. 

Importing a single package allows us to work with the date and time API.
In this lesson you will find many helpful examples and exercises, so make sure to practice what you’ve learned! 

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. If you still have questions, we’re always here to help! 

*The exercise descriptions are to be found in the PDF document at the end of this post.

In the current lesson, we take a close look at exception handling and why it’s important in software engineering.

What are exceptions? We’ve all seen one, there is no way to write completely bug-free code. In short an exception is a problem that arises during the execution of the program. 

Exceptions simplify code construction and maintenance and allow problematic situations to be processed at multiple levels.

In Java exceptions are objects. The base for all exceptions is the Throwable class – it contains information about the cause of the exception, its description, and the stack trace.

There are two types of exceptions – checked (also known as compile-time exceptions), and unchecked (also known as runtime exceptions).

Exceptions can be handled by the try-catch construction. The try-finally block is also used, especially when we want to ensure the execution of a given block of code. 

To raise an exception, we use the throw keyword. When an exception is thrown the program execution stops, and the execution travels over the stack until a matching catch block is reached to handle it. 

In this lesson you will find many helpful examples and exercises, so make sure to practice what you’ve learned! That’s the only way to grasp the concept at hand.

In the current lesson, you will learn the four pillars of Object-Oriented Programming (OOP).

Svetlin Nakov will explain to you what are the four main OOP Principles. He talks about the concepts of encapsulation, inheritance, abstraction, and polymorphism. Later, you will learn how to compare different objects in Java using equals() and compareTo() methods. Make sure that you understand everything since this is one of the most important topics in the programming world!

You will find many helpful examples and exercises, so make sure to practice what you’ve learned!

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video.

*The exercise descriptions are to be found in the PDF document at the end of this post.

In the current lesson, you will learn the foundations of Object-Oriented Programming (OOP).

Svetlin Nakov will go over the topics of defining simple classes, conventions, and best practices in doing so, creating objects of these classes, object references, and what is the difference between an object and a class.

Later on in the lesson, you will become familiar with data fields and access modifiers, and of course – constructors, getters, and setters, which are the building blocks of every class. By the end of the lesson, you will also have a good understanding of the term static, which you’ve surely encountered multiple times so far.

You will find many helpful examples and exercises, so make sure to practice what you’ve learned!

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this post.

The current lesson provides a great overview of objects and classes if you are a beginner on the topic. With it, you will make your first steps in the world of Object-Oriented Programming (OOP), which is one of the most widely-used programming paradigms in modern programming.

By the end of the lesson, you will be familiar with the objects and classes work and their purpose. You will also know the different parts of a class – methods, constructors, getters and setters, fields, etc.

You will find many helpful examples and exercises, so make sure to practice what you’ve learned!

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video.

 

*The exercise descriptions are to be found in the PDF document at the end of this post.

In this video we go in depth explaining maps, lambda and the stream API. All of these three topics are extremely important for every beginner programmer to learn as they are part of the pillars of programming, just like the rest of the topics in the current course. 

By the end of the lesson, you will be familiar with three different types of maps in Java – the HashMap, the LinkedHashMap and the TreeMap. All have their special traits and serve a specific purpose, which George explains very well. 

Then you will dive deep into lambda expressions and see how important they are when we are doing certain operations with maps. 

Finally, George will touch up on another important topic when it comes to maps – the Stream API, which provides many methods for easy querying of a collection. 

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video.

*The exercise descriptions are to be found in the PDF document at the end of this post.

In this lesson introduces strings and provides an in-depth explanation of text processing in Java. It includes several very important topics surrounding strings – the StringBuilder class, concatenation and why it’s a slow operation, the methods concat(), indexOf(), contains(), split(), replace(), and many more. 

As always, we advise you to pause the video right before the solving part of each problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this article.

By now you’ve learned all about arrays, but did you know there are more data structures in programming? Lists are one of the most popular data structures in programming, as they allow for flexibility. Unline arrays, their length is not fixed and you can insert and delete elements at any point! Cool, right?

As always, we advise you to pause the video right before the solving part of a problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this post.

In this free Java Foundations video, we will review another very important paradigm in the programming universe – Methods. We will find a few ways in which will make our code more organized and readable. Also, we are going to learn how to extend the functionality of our code.

Each of these topics is explained with many real-life examples and hands-on exercises. As always, we advise you to pause the video right before solving part of a problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this post.

In this free Java Foundations video, we explain some of the fundamental concepts in programming. For example – we will review what arrays are, how we use them, why are they helpful and how we can manipulate their elements.

Each of these topics is explained with many real-life examples and hands-on exercises. As always, we advise you to pause the video right before solving part of a problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this post.

In this free Java Foundations video, we explain some of the fundamental concepts in programming. For example – we will review how to use data types, variables, how variables are stored in the memory, how to convert from one data type to another. 

Each of these topics is explained with many real-life examples and hands-on exercises. As always, we advise you to pause the video right before solving part of a problem and try to do the exercises on your own first. Then, if you have difficulties, just watch the provided solutions in the video. 

*The exercise descriptions are to be found in the PDF document at the end of this post.