EPTA little bit about me
I'm a fairly new programming student myself. I have most of my experience in programming in C++ and Ruby, although I have dabbled in many other languages. I've done many of the programming challenges on projecteuler and InterviewStreet and would recommend both of those sites to people who are looking for some programming challenges (links below). So back to my point, because I am a newbie too what I say may not necessarily be the best way to do something, hell, it may even be one of the worst. That doesn't detract from my overall goal of getting some of you guys immersed in programming.
- http://projecteuler.net/
- https://www.interviewstreet.com/challenges/
Programs that you will be using
This section explains the material that you should download. I'll try and explain the steps to set all of this up the best that I can.
To start off you need to install Ruby itself. I recommend doing that here: http://rubyinstaller.org/downloads/
You need to click the link labeled "Ruby 1.9.3-p194" on that page as this is the most recent version of Ruby without all of the extra stuff attached.
Once you've finished installing Ruby open up your command prompt. Now we are going to install your IDE aka Integrated Development Environment which is where you are going to be writing your code.
In your commend prompt type the following line "gem install redcar" this will install redcar.
Now that you have installed redcar you can run it. You can do this two ways - you can use search to find redcar and click to run it (it should be a batch file within your Ruby folder, doing this can let you create yourself a neat little icon for redcar) or you can run it through command prompt. Simply type "redcar" into command prompt to run it.
For any more questions you could have about installation, here are a couple of links you can look over for additional information:
- http://www.ruby-lang.org/en/downloads/
- https://github.com/redcar/redcar/wiki/installation
Awesome! You have just set up your own IDE for Ruby and you're ready to code!
Your first program!
So, you should have redcar opened and your screen should look something like this:
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![[image loading]](http://i.imgur.com/99GMO.png)
What you want to do now should seem fairly obvious - but go ahead and create a new file.
To precursor your first program I'd like to throw a few things out there for those who may have some prior programming experience - Ruby is an interpreted language so for this simple stuff we will not be using any 'Require' statements (equivalent of include in C).
So to start off really simple, type into redcar the following:
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puts "hello"
Now to test this go over to the drop-down bar and under plug-ins select execute. You will see another tab pop up and this is your build log. It should simply say "hello" in it. Congratulations, your code ran successfully!
Another way to test your code is to run it through command prompt. This is a bit more time consuming though. So let's say you want to do this, first you want to save your file. I'm going to save mine in my Ruby folder - labeled Ruby193.
The next step is to set command prompt to run from that folder, so you use the code cd to change the destination and then type the folder destination after that. So once you find where you've saved your program find it's destination and type something similar to my example below:
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cd C:\Ruby193
Awesome, command prompt is now able to run from this folder, now you want to actually run your program, to do that type:
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ruby hello.rb
Simply replace hello.rb with whatever you saved your program as and you will see your program run right in front of you.
Congratulations! You've just created and ran your first Ruby program!
Getting your hands dirty
Now let's move onto some of the more juicy things, shall we?
In Ruby there are no types - everything is an object. This basically means that unlike most other languages when you are declaring variables you don't need to assign them. In other languages if you wanted to create a new variable that is an integer you would do something like this:
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int x = 0 ;
However in Ruby, you don't need to do that, you only have to type this:
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x = 0
It's a bit simpler, and having no type casting has it's advantages and it's disadvantages, but we'll worry about that later.
For now let's do some simple addition and experiment with types.
type the following into redcar:
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x = 4
y = 5
z = x + y
puts z
So, yeah. Run that and you should get an output of "9". What you've just done is created three variables, x, y, and z. You'll notice that they are integers. Now try this:
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x = 4
y = 5.0
z = x + y
puts z
This may not mean much to you, but those are actually two different types of variables! adding a decimal place to the y value actually makes it a float type and the fact that they add together is super cool - I'm bringing this up because I'd like to preface how awesome Ruby is with the flexibility it has with variables.
Next I'll have you guys play around with strings a little bit, try typing this in:
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x = "Bat"
y = "man"
z = x + y
puts z
Ruby has MANY awesome abilities to manipulate strings in cool ways. Since everything is an object in Ruby these are called methods - here try this method out real quick:
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x = "Bat"
y = "man"
z = x + y
puts z.reverse
Now to move onto showing some examples of arrays and iterations done in Ruby. Type the following into redcar:
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x = [2, 5, 6]
x.each do
puts x
end
Your result should be:
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2
5
6
2
5
6
2
5
6
Notice that it repeated the numbers 2, 5, 6 three times. This is because it ran the loop three times - once for each item within the array, x. When using puts if you put in the variable name it will spit out all of the information and that can be annoying. What if you only want to output each of the values in the array once?
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x = [2, 5, 6]
x.each do |n|
puts n
end
Your output should be:
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2
5
6
Now, you should notice that the first code segment is pretty different from the second. To begin with, what's that |n|? That is a new variable that is assigned the value of the variable at the position of the loop that you are in. This may sound confusing (due to my bad wording) but it basically means that as your code runs through the loop it becomes the value of the variable in that position in the loop. So as it runs through each value within x it becomes the value of that position. Then you put n out there and it outputs each value in x.
That was pretty neat if I do say so myself! Anyway, this was just something short I thought I'd prepare to have you mess around a bit before I release you out into the vast world of Ruby.
Additional repositories
I hope you're interested as I have prepared a few awesome links below to further your learning!
- http://ruby-doc.org/
+ Show Spoiler +This will be your best friend for finding out more syntax and reserved words in Ruby. Take a gander into the 'Core' section at the top of this page to find the entire Ruby source code at your disposal. If you're looking for something neat to mess around with I suggest taking a look in the 'String' section within 'Core' to find some fun methods to play around with in Ruby. - http://tryruby.org/levels/1/challenges/0
+ Show Spoiler +This is a pretty well written hands-on tutorial to help you really get the basics of Ruby down. I highly recommend that you do it! - http://www.sapphiresteel.com/ruby-programming/The-Book-Of-Ruby
+ Show Spoiler +This is an entire FREE online book that you can download in PDF that is incredibly descriptive and will cover everything you will need to know about Ruby. It has amazing details and examples so you can gets some hands-on experience as to what is being talked about and the writer is extremely entertaining as well. - http://pragprog.com/book/ltp2/learn-to-program
+ Show Spoiler +This is a book that I have not personally read - but I assume it must be great! This source was supplied from: http://www.teamliquid.net/blogs/viewblog.php?topic_id=337732#7
Closing thoughts
I know my first hands on examples didn't cover base on a lot of things (please don't hunt me down for not mentioning classes in an object-only language) - I was mostly trying to show off some programming fundamentals and be able to help people execute their own program instead of teaching them programming fundamentals (that is what the links are for).
I am also sure that there are other wizards out there who know much more than I who would be glad to extend upon any of the points that I've made and also might even drop by and throw in some tid bits that could be included in the OP. If you're one of those wizards who think that I have left something important out feel free to PM me and I'll be glad to include it - also feel free to toss it down in a comment if that suits your fancy.
Also - feel free to PM me any questions or concerns you might have, I'd love to share more information or even ooh and aah at your creations if you wind up making something awesome!
I hope you guys have as much fun reading this as I did creating it. Happy posting
ruby
