Wtd at 02:48, 11 October 2008

2008-10-11T02:48:24Z

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== Everything in [[Ruby]] is an object. ==

No, really.

You may have used [[Java]], and thought you were doing [[object-oriented]] programming, but [[Java]] is only partially [[object-oriented]]. There are still primitive values like int, float, double and such which aren't.

This is probably the best thing about [[Ruby]], and it's one that warrants being mentioned upfront. That said, if you have little to no [[object-oriented]] programming experience, [[Ruby]] is still friendly.

== Hello, [[Ruby]]! ==

<pre>puts "Hello, Ruby!"</pre>

Pretty simple. The puts method prints an object, followed by a newline, much like [[Java]]'s System.out.println. [[Ruby]]'s puts method is smarter, though. It will only add a newline if one isn't already included.

<pre>puts "Hello, Ruby!\n"</pre>

Would produce exactly the same output as the previous code example.

Additional methods exist as well:

<pre># this is a comment, by the way...

# print doesn't append any extra newlines
print "Hello, Ruby!\n"

# printf works like the function of the same name in C
printf "%s, %s!\n", "Hello", "Ruby"</pre>

== Friendly Ruby ==

Now, we can output a string. We next need a name from the user so [[Ruby]] can be friendly.

<pre>puts "Hello, Ruby!"
print "I'm "
name = gets
puts "Ruby says, \"hello, #{name}\""</pre>

The first and second lines look familiar. The third line calls the gets method which reads a string from standard input and assigns it to the variable "name".

The fourth line is probably the most novel so far. In the string, #{name} indicates that the variable name should be inserted into the string. This construct is incredibly flexible, and this is only a trivial demonstration of what it can do.

Hello, Ruby! - Revision history

Wtd at 02:48, 11 October 2008