Hello world (first method)

Thufir · November 3, 2007, 4:53am

For the following:

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>type HelloWorld.rb
#5.times { print “Odelay!” }

def fact(n)
if n <= 1
1
else
n * fact(n - 1)
end

    print n

end

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>HelloWorld.rb

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>HelloWorld.rb
1C:/Documents and Settings/nsaunders/Desktop/HelloWorld.rb:10:in *': nil can't be coerced into Fixnum (TypeError) from C:/Documents and Settings/nsaunders/Desktop/HelloWorld.rb: 10:infa
ct’
from C:/Documents and Settings/nsaunders/Desktop/HelloWorld.rb:
10:in `fa
ct’
from C:/Documents and Settings/nsaunders/Desktop/HelloWorld.rb:
17

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>

Does there need to be class defined to call the method?

thanks,

Thufir

Thufir · November 3, 2007, 4:59am

I believe so and u need to create an object and call the method using
the object

class Test

def fact
…
end

end

obj = Test.new
obj.fact

I wish this will help

Thufir · November 3, 2007, 5:04am

Thank you

In the interim, I got better results:

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>type HelloWorld.rb
#5.times { print “Odelay!” }

n=5

def fact(n)
if n <= 1
1
else
n * fact(n - 1)
end
end

print fact(20)

def hello(i, aString)

    i.times {print "\n" + aString + "\n"}

end

hello(6, “success”)
C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>HelloWorld.rb
2432902008176640000
success

success

C:\Documents and Settings\nsaunders\Desktop>
C:\Documents and Settings\nsaunders\Desktop>

Once I took the plunge, it’s quick progress so far! I can change a
line, then just run it. I haven’t gotten used to the idea of the irb,
for now just going back and forth between the DOS prompt and notepad
works smoothly.

-Thufir

Thufir · November 3, 2007, 5:08am

Quoth Shuaib Z.:

end

obj = Test.new
obj.fact

I wish this will help

Wrong.

I don’t know what the OP is doing wrong (from the source, he isn’t
calling
fact() ever. However, defining a method without a class really defines
it as
part of Kernel (which methods can be called without Classname.method).

Thufir · November 3, 2007, 5:14am

On Nov 2, 8:59 pm, Shuaib Z. [email protected] wrote:

I believe so and u need to create an object and call the method using
the object

class Test
[…]

I’d like to have two .rb files:

Test.rb
useTest.rb (or would that be UseTest.rb ?)

How would I do that, please?

thanks,

Thufir

Thufir · November 3, 2007, 7:02am

Include the test.rb file in the useTest.rb file like this:

require ‘test’

S

Thufir · November 3, 2007, 7:40pm

Thanks

C:\code>
C:\code>
C:\code>
C:\code>
C:\code>
C:\code>
C:\code>dir
Volume in drive C has no label.
Volume Serial Number is 0491-510F

Directory of C:\code

11/03/2007 11:34 AM .
11/03/2007 11:34 AM …
11/03/2007 11:35 AM 122 doFactorial.rb
11/03/2007 11:34 AM 114 factorial.rb
11/03/2007 11:32 AM 353 Hello.rb
11/03/2007 11:26 AM 319 Hello.txt
4 File(s) 908 bytes
2 Dir(s) 28,968,902,656 bytes free

C:\code>type doFactorial.rb
require ‘factorial’

x=20

print "\n\n\nThe factorial of "
print x
print " is "
print fact(x)
print “\n\n\n\n”

C:\code>
C:\code>type factorial.rb
def fact(n)
if n <= 1
1
else
n * fact(n - 1)
end
end
C:\code>
C:\code>doFactorial.rb

The factorial of 20 is 2432902008176640000

C:\code>
C:\code>

Also, when I got home I read poignant ruby and found it

-Thufir

Thufir · November 3, 2007, 10:09am

Thufir wrote:

line, then just run it. I haven’t gotten used to the idea of the irb,
for now just going back and forth between the DOS prompt and notepad
works smoothly.

There’s nothing wrong with that. I never use irb (or interactive
sessions in other languages I program in). I find them unwieldy and too
much of a hassle to bother with.

If notepad doesn’t provide automatic indenting, then you should try to
obtain a text editor that does. It makes typing in code much easier.
The way it works is that when you hit return and the next line should be
indented, the text editor automatically indents the cursor on the next
line–you don’t have to type any spaces. Likewise, if you type in a
line of code that is indented, and the next line shouldn’t be indented,
then the text editor automatically dedents the next line.