Problems with Ruby under Windows XP

[Yalin]

I have installed ruby with "ruby181-11.exe" on Windows XP and wanted to try
some code samples from the Ruby Programmers Guide, but without success. If I
run following code, I don't get any output on console:

------------------------------------
a = [ 1, 'cat', 3.14 ] # array with three elements
# access the first element
a[0] » 1
# set the third element
a[2] = nil
# dump out the array
a » [1, "cat", nil]

 

[Simon Strandgaard]

I have installed ruby with "ruby181-11.exe" on Windows XP and wanted to try
some code samples from the Ruby Programmers Guide, but without success. If I
run following code, I don't get any output on console:

[snip]

welcome to Ruby ;-)


try

a = [1, 'cat', 3.14]
p a[0]
a[2] = nil
p a


on my machine (executing 'ruby example.rb') it outputs

1
[1, "cat", nil]

 

[Yalin]

Thanks,

but what is the reason for this problem?
The same is, e.g. when you use the "inspect" or the "to_s" message of an
object.

--
Yalin

I have installed ruby with "ruby181-11.exe" on Windows XP and wanted to try
some code samples from the Ruby Programmers Guide, but without success. If I
run following code, I don't get any output on console:

[snip]

welcome to Ruby ;-)


try

a = [1, 'cat', 3.14]
p a[0]
a[2] = nil
p a


on my machine (executing 'ruby example.rb') it outputs

1
[1, "cat", nil]

 

[Simon Strandgaard]

On Fri, 05 Mar 2004 16:18:50 +0100, Yalin wrote:
[snip]

but what is the reason for this problem?
The same is, e.g. when you use the "inspect" or the "to_s" message of an
object.

p "hello" # "hello"
puts("hello".inspect) # "hello"

All objects has an .inspect method. Even though we
doesn't define it ourselves then its there.
For instance a slightly more complex example..
then .inspect will do a nice output of the internal state
of the object.

class Person
def initialize(firstname, lastname)
@firstname = firstname
@lastname = lastname
end
end
person = Person.new("Albert", "Einstein")
p person

#<Person:0x810a800 @firstname="Albert", @lastname="Einstein">

 

[Dave Thomas]

Thanks,

but what is the reason for this problem?
The same is, e.g. when you use the "inspect" or the "to_s" message of
an
object.

If you want Ruby to output a value, you need to say something like

puts value

Simply saying

value

doesn't generate any output.

In the book, we add annotations to some code listing to show the values
of expressions on those lines. So we might have

value = 123
value + 2 # => 125

The reason we did that was that it saved a lot of space, comared with

value = 123
puts(value+2)

generates:

125


It's also easier to track what values ti in with which expressions.

Sorry it's confusing



Cheers

Dave