Java Tutorial for Beginners
Mosh is a software engineer with over two decades of
experience and has taught over 3 million people how to code.
He has designed this course for anyone who wants to learn
Java. If you're a beginner, don't worry - Mosh promises to make
Java super simple and hold your hand through this course. He
hopes you'll stick around and learn this beautiful and powerful
programming language.
The Anatomy of a Java Program
In this Java tutorial, we'll be looking at the basics of a Java
program. The smallest building block in Java programs are
functions. If a function is a block of code that performs a task,
think of the buttons on the remote control of your TV. Every
Java program should have at least one function and that
function is called main .
Writing Java Code
After the parentheses, we have a pair of curly braces and
inside these braces, we write the actual Java code. Every Java
program should have at least one function and that function is
called main . So, main is the entry point to our programs.
Whenever we execute a Java program, the main function gets
called and the code inside this function gets executed.
Downloading IntelliJ IDEA
IntelliJ IDEA is absolutely free and it's more than enough for
this course, so download it now.
Download IntelliJ IDEA
A class is a container for related methods, so we use classes
to organize our code. By the same token, we have a concept
called package, and we use a package to group related
classes.
As our applications grow, we're going to end up with hundreds
or even thousands of classes, so we should properly organize
, these classes into packages. The base package for a Java
project is the domain name of your company in reverse.
The code editor might look a little bit intimidating at first, but
trust me it's really easy and you're going to learn about it
throughout this course. For now, just type a base package for
your project; it can be your name or whatever, it doesn't really
matter.
Marsh has put together a comprehensive cheat sheet with
summary notes that you can download below this video.
IntelliJ is building our application and we can see the result in
this little terminal window. So, here's our "Hello World"
message. That was our first Java program.
Next, I'm going to explain how Java code gets executed under
the hood.
IntelliJ uses the Java compiler to compile our code into a
different format called Java bytecode. This Java code is
platform-independent, meaning it can run on Windows, Mac,
Linux, or any operating system that has a Java Runtime
Environment. Java applications are portable, or platform-
independent.
Java was developed by James Gosling in 1995 at Sun
Microsystems, which was later acquired by Oracle in 2010.
Currently, close to 9 million developers worldwide use Java.
About 3 billion mobile phones run Java, as well as 120 million
TV sets and every Blu-ray player. The average salary of a Java
developer is just over $100,000 per year in the US.
This course is the first part of my complete four-part Java
series. Each part is about three to four hours long, so you can
easily complete it in a day or two. The first part will give you a
solid foundation on how to start programming in Java. In the
second part, we'll talk about Object-Oriented Programming,
which is a style used in most, if not all, Java applications. The
third part will cover Core Java APIs, or Application Programming
Interfaces.
Once you learn all this, I'm going to give you a project. You're
going to build a mortgage calculator on your own, so make
Mosh is a software engineer with over two decades of
experience and has taught over 3 million people how to code.
He has designed this course for anyone who wants to learn
Java. If you're a beginner, don't worry - Mosh promises to make
Java super simple and hold your hand through this course. He
hopes you'll stick around and learn this beautiful and powerful
programming language.
The Anatomy of a Java Program
In this Java tutorial, we'll be looking at the basics of a Java
program. The smallest building block in Java programs are
functions. If a function is a block of code that performs a task,
think of the buttons on the remote control of your TV. Every
Java program should have at least one function and that
function is called main .
Writing Java Code
After the parentheses, we have a pair of curly braces and
inside these braces, we write the actual Java code. Every Java
program should have at least one function and that function is
called main . So, main is the entry point to our programs.
Whenever we execute a Java program, the main function gets
called and the code inside this function gets executed.
Downloading IntelliJ IDEA
IntelliJ IDEA is absolutely free and it's more than enough for
this course, so download it now.
Download IntelliJ IDEA
A class is a container for related methods, so we use classes
to organize our code. By the same token, we have a concept
called package, and we use a package to group related
classes.
As our applications grow, we're going to end up with hundreds
or even thousands of classes, so we should properly organize
, these classes into packages. The base package for a Java
project is the domain name of your company in reverse.
The code editor might look a little bit intimidating at first, but
trust me it's really easy and you're going to learn about it
throughout this course. For now, just type a base package for
your project; it can be your name or whatever, it doesn't really
matter.
Marsh has put together a comprehensive cheat sheet with
summary notes that you can download below this video.
IntelliJ is building our application and we can see the result in
this little terminal window. So, here's our "Hello World"
message. That was our first Java program.
Next, I'm going to explain how Java code gets executed under
the hood.
IntelliJ uses the Java compiler to compile our code into a
different format called Java bytecode. This Java code is
platform-independent, meaning it can run on Windows, Mac,
Linux, or any operating system that has a Java Runtime
Environment. Java applications are portable, or platform-
independent.
Java was developed by James Gosling in 1995 at Sun
Microsystems, which was later acquired by Oracle in 2010.
Currently, close to 9 million developers worldwide use Java.
About 3 billion mobile phones run Java, as well as 120 million
TV sets and every Blu-ray player. The average salary of a Java
developer is just over $100,000 per year in the US.
This course is the first part of my complete four-part Java
series. Each part is about three to four hours long, so you can
easily complete it in a day or two. The first part will give you a
solid foundation on how to start programming in Java. In the
second part, we'll talk about Object-Oriented Programming,
which is a style used in most, if not all, Java applications. The
third part will cover Core Java APIs, or Application Programming
Interfaces.
Once you learn all this, I'm going to give you a project. You're
going to build a mortgage calculator on your own, so make
