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In this video we will explore the development environment we will be using for the rest of the course, Workspaces. We will write, compile and run a command line program that will introduce ourselves.
It's not an error!
- Not to worry, the
Picked up JAVA_TOOL_OPTIONS: -Xmx128mis not an error on your part, we recently just tweaked our setup to have more memory allocated. Don't fret that mine looks different!
Additional Content
- Learn more about the command line in the Console Foundations course
[MUSIC]
0:00
Hello and welcome.
0:04
I'm Craig, and I'm a developer.
0:05
For this course, it doesn't matter if you
have any programming experience at all.
0:07
I'll be introducing you to some
very common tools available in
0:12
almost every programming language
that you might encounter.
0:15
We'll be doing our exercises in Java,
and I'd like you to approach this
0:19
as if you were attempting to
learn a foreign language.
0:23
I'll introduce you to the rules or
syntax of the language as you need it,
0:26
we will also discuss the oddities
that you might encounter.
0:30
As we go through different
parts of this course,
0:33
you'll start to recognize words and
concepts in other parts of the language
0:36
much like you would in
a language immersion program.
0:40
Just like when you're wandering around
a foreign country where you're just
0:43
learning the language,
you'll come across words and
0:46
phrases that you aren't familiar with and
that's okay.
0:48
Focus on the topics we're covering and
don't worry about the other parts.
0:52
As we're cruising along,
I might ask you to ignore some things, but
0:56
I promise we'll get back to
it when the time is right.
0:59
You might not have noticed it yet but
there is speed controls on your video.
1:02
Please feel free to speed me up and
make a pretty good chipmunk or
1:06
slow me way down as you feel necessary.
1:09
I won't take any offense.
1:14
I promise.
1:15
Also, I've added helpful
links in the teacher's notes
1:16
that will allow you to learn even more,
sound good?
1:19
So without further ado,
let's get started with our task at hand.
1:23
Just like most foreign language classes,
1:27
the first thing we're going to learn
is how to introduce ourselves in code.
1:29
So, what we'll do is we'll write out or
print, hello my name is, and
1:34
then your name, to the screen.
1:38
Speaking of introductions,
1:40
allow me to introduce you to where we'll
be coding during this course, Workspaces.
1:42
If you click the launch Workspaces
button right next to this video,
1:47
you'll see a new browser open
with our programing environment.
1:50
I'll head over there with you.
1:53
So this is a Workspace,
and it's all yours.
1:56
You'll see up here that there's a tabbed
interface of files that you have open.
2:00
And over here is a list of files
that you have available to you.
2:04
I've gone and created a file and
2:07
got it all set up with a nice starting
point to begin writing our application.
2:08
It's called Introductions.java.
2:12
Let's open it up and take a peek.
2:13
I've left a note or a comment right here.
2:18
Comments in Java start
with two forward slashes,
2:22
everything after the slash
was ignored by Java.
2:25
So they're used by programmers to explain
what their code is trying to accomplish in
2:27
clear English or to leave notes for
other programmers.
2:31
Now one goal of programming is for
your code to be as clear as possible, so
2:34
that it doesn't require comments.
2:38
However, as we're getting started here
feel free to leave comments whenever you
2:39
want to remind yourself of what it
is that we're attempting to do.
2:43
Now, remember how I warned you
that you'll come across words or
2:46
phrases that you aren't familiar with and
that I might ask you to
2:49
ignore some parts of code until later,
we're at one of those points.
2:52
Every Java program has some setup
that needs to happen and for now,
2:56
I've done that for you.
2:59
But don't worry about understanding
most of the pre-written code that's on
3:00
the screen, it's just the setup that we
need to do to start writing our own code.
3:03
However, the one bit of code I've written
that I want you to take a closer look at
3:07
is this line right here.
3:11
But don't worry exactly
about how this code works.
3:14
What you need to know is that it creates a
Java object, which we'll talk about later,
3:17
which has a method that
allows us to write out
3:21
text to the terminal which is down here.
3:23
I'd like to take a quick break and already
acknowledge, as well as remind you that I
3:26
just threw out a mouthful of new terms
like objects and methods and like I said,
3:30
don't worry, we'll color them in much
greater detail in the following course.
3:34
But for now, I just want you to continue
immersing yourself in this language.
3:38
I'll explain the concepts when
they're important to the task at hand.
3:42
So like I said thanks to the setup, I've
done we have access to the console object.
3:45
We can use this console object
to print text to the screen.
3:50
Objects like console have methods
that let them perform actions, and
3:53
the action that we want to do right
now is print some text to the screen.
3:57
Console's method for printing text on the
screen is called printf, so let's use it.
4:01
First we'll type console, and
4:07
then a period to access its
methods in the word take printf..
4:09
We're gonna call the method
by doing open parenthesis.
4:14
Now we're gonna do double quotes and
write the text out that we wanna write, so
4:17
we're gonna say, hello my name is Craig.
4:21
We're gonna end the double quote, and
then we're gonna end the parenthesis and
4:24
then we're gonna put a semicolon to
signify that the statement is complete.
4:28
You might have noticed that as I edited
the file there's a little dot up here
4:32
signifying that the file has been edited.
4:36
I'm going to go ahead and
I'm going to save from the file,
4:38
I mean I'm going to click File,
and I'm going to click Save and
4:41
you'll notice that in the future you
can use Cmd+S or Ctrl+S on a window.
4:43
Okay, so let's see our code in action.
4:48
Now, Java is a compiled language,
4:50
which means that we have to run a compiler
program to turn our human readable Java
4:52
code into computer readable
code before we run it.
4:56
So let's compile our
introductions program.
4:59
To do that at the console,
we type javac and
5:02
then the name of the file
which is Introductions.Java.
5:07
Java C is short for Java compiler.
5:14
So this line is telling the Java
compiler to convert or compile
5:17
the code in the file Introductions.Java
into an executable file.
5:20
So I'm going to press Enter.
5:26
And if we take a look at the files in
this directory using the LS command,
5:29
see that there is now a file
called Introductions.class.
5:33
By the way, I should mention here
that LS stands for list, and
5:39
it allows you to list
files in a directory.
5:42
We're gonna use a few terminal
commands on this course, and
5:45
I'll teach you everything
you need to know for it.
5:48
But if you wanna learn more about
using the terminal, check out our
5:50
course called Console Foundations
which is linked in the teachers out.
5:52
Now to run our program,
we simply type java Introductions.
5:56
Now notice the command that I
type here is java, not javac.
6:04
Java runs the program it only needs the
name of the class, without the extension.
6:09
Javac required that .java,
and Java does not.
6:14
So I wanna press Enter.
6:18
And here on the screen we see our output,
the introduction.
6:20
Great job.
6:24
We now have our first compiled program.
6:25
You've been learning a ton.
6:28
Before we move on and learn even more,
6:30
let's do an exercise to review some
of the things we've learned thus far.
6:32
Before we get there, let me just remind
you that there is a community that you can
6:36
and should lean on while
going through this course.
6:40
If you have questions,
it's likely someone else has them too and
6:44
has maybe even answered them.
6:47
Learning how to ask questions and
6:50
find answers is in my personal opinion
the best way to learn anything.
6:51
If you're coming to this course
with some Java experience,
6:56
you might have used an IDE or
Integrated Development Environment.
6:59
Now those are a set of tools which
greatly simplify the development
7:03
process through code completion and
many other bells and whistles.
7:06
As handy as IDEs are,
7:11
I'd like to request that you still
follow along in the Workspace.
7:13
As I think there's benefit in learning and
gaining confidence in doing things
7:17
all by yourself and
removing some of the magic of that IDE.
7:21
We'll go over IDEs in a future
course when the time is right.
7:24
Okay, now back to that exercise.
7:28
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