From: Arlen Cuss <celtic@...>
Date: 2008-04-08T22:42:23+09:00
Subject: Re: simple, simple array question

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Hi,

I'm so tired, so here's a succinct answer:

`capitalize!' (with the exclamation mark on the end) actually changes `x'
itself:

>> a = "boo"
=> "boo"
>> a.capitalize!
=> "Boo"
>> a
=> "Boo"
>>

Notice how `a' has a new value. Now, what if we try to capitalize! again?

>> a.capitalize!
=> nil
>> a
=> "Boo"
>>

It returns nil. `a' is still "Boo" - the thing is, capitalize! returns nil
because `a' didn't change. With your example, `This' is already capitalized,
so no change occurred. What you really want is `x.capitalize' - it just
returns the value of x capitalized, whatever that is:

>> a = "boo"
=> "boo"
>> a.capitalize
=> "Boo"
>> a
=> "boo"
>>

It also doesn't change `x' - not that it would matter much in your given
example.

Also, though it's probably just your test, but note that you're not saving
the result of `collect' anywhere. As an example:

>> a = %w(This is a test.)
=> ["This", "is", "a", "test."]
>> a = %w(This is a test)
=> ["This", "is", "a", "test"]
>> a.collect {|x| x.capitalize}
=> ["This", "Is", "A", "Test"]

We get this answer, but ...

>> a
=> ["This", "is", "a", "test"]

It's still lowercase! So we can use the collect! method to alter the
original:

>> a.collect! {|x| x.capitalize}
=> ["This", "Is", "A", "Test"]
>> a
=> ["This", "Is", "A", "Test"]
>>

Or you could assign the result of `collect'.

And I'm out for the night.

HTH,
Arlen

On Tue, Apr 8, 2008 at 11:35 PM, Peter Bailey <pbailey@bna.com> wrote:

> Hi,
> I need to cap-and-lowercase words in strings of XML data. Why is this
> happening in this test?
>
> stuff = [ "This", "is", "a", "test" ]
> stuff.collect { |x| puts x.capitalize! }
>
> I get:
>
> nil
> Is
> A
> Test
>
> Program exited with code 0
>
> What's with the "nil?"
>
> Thanks,
> Peter
> --
> Posted via http://www.ruby-forum.com/.
>
>

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