Ruby string


#1

string = “this is a String”
string.capitalize = “This is a string”
That works but changes my capital “a String” to lowercase.

I only want to capitalize first letter.
So I try"
string[0…0].capitalize
irb => “T”
OK
string[0…0].capitalize!
irb => “T”
irb string
irb => “this is a string”

I am a noob but I don’t get that.
Where is my capitalised first letter.

Anybody?


#2

Peter wrote:

string[0…0].capitalize!

string[0, 1] = string[0, 1].capitalize


#3

Alex Barrett wrote:

Peter wrote:

string[0…0].capitalize!

string[0, 1] = string[0, 1].capitalize

Thanx


#4

unknown wrote:

I can’t think of a better way to do this than what’s already been
posted, though it really does feel like there should be.

Actually, there is :S
You can save three whole keypresses (or just two if you dislike
whitespace) by doing:

string[0, 1] = string[0, 1].capitalize


#5

Hi –

On Sat, 8 Apr 2006, Peter wrote:

irb => “T”
irb string
irb => “this is a string”

I am a noob but I don’t get that.
Where is my capitalised first letter.

What you’ve done is to create a new string, consisting of the single
character ‘t’. Then you’ve done an in-place capitalize on that
string; then you’ve discarded it :slight_smile:

I can’t think of a better way to do this than what’s already been
posted, though it really does feel like there should be.

David


David A. Black (removed_email_address@domain.invalid)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

“Ruby for Rails” coming in PDF April 15, and in paper May 1!
http://www.manning.com/black


#6

Alex Barrett wrote:

string[0, 1] = string[0, 1].capitalize

Curses, trust me to repost the same thing. I meant:

string[0] = string[0, 1].capitalize

Must remember to check my pasting before submitting.


#7

On Sat, 8 Apr 2006, removed_email_address@domain.invalid wrote:

OK
string[0…0].capitalize!
irb => “T”
irb string
irb => “this is a string”

What you’ve done is to create a new string, consisting of the single
character ‘t’. Then you’ve done an in-place capitalize on that
string; then you’ve discarded it :slight_smile:

Another not-so-brilliant way to do is to put the created string back to
the original string by doing this:

string[0…0] = string[0…0].upcase

I can’t think of a better way to do this than what’s already been
posted, though it really does feel like there should be.

I agree.


#8

Hi –

On Sat, 8 Apr 2006, Alex Barrett wrote:

Alex Barrett wrote:

string[0, 1] = string[0, 1].capitalize

Curses, trust me to repost the same thing. I meant:

string[0] = string[0, 1].capitalize

Must remember to check my pasting before submitting.

And I should remember to read the rest of the thread before replying
:slight_smile:

David


David A. Black (removed_email_address@domain.invalid)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

“Ruby for Rails” coming in PDF April 15, and in paper May 1!
http://www.manning.com/black


#9

I love Ruby but this is cumbersome.
There are plenty of situations where people want to
capitalize only the first letter.

By saying:
string[0,1].capitalize! with ! should read like:
Capitalize only the first character within string ‘string’
Or is that stupid thinking.
Its a method on the first character.

Funny.
But thanks all.


#10

Hi –

On Sat, 8 Apr 2006, Alex Barrett wrote:

unknown wrote:

I can’t think of a better way to do this than what’s already been
posted, though it really does feel like there should be.

Actually, there is :S
You can save three whole keypresses (or just two if you dislike
whitespace) by doing:

string[0, 1] = string[0, 1].capitalize

Isn’t that the same as what you’d already posted?

David


David A. Black (removed_email_address@domain.invalid)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

“Ruby for Rails” coming in PDF April 15, and in paper May 1!
http://www.manning.com/black


#11

Peter wrote:

I love Ruby but this is cumbersome.
Well, i don’t think this is a Ruby specific behavior. I have just tried
the same thing in Python:

s = “this is a String”
s.capitalize()
‘This is a string’

i.e. it has absolutely the same semantics as in Ruby.

There are plenty of situations where people want to
capitalize only the first letter.
The problem is not the capitalization of the first letter (as this
works), but rather that it turns the other first-letters to lowercase.
I don’t know why the capitalize() function is defined like this - both
in Python and Ruby…

By saying:
string[0,1].capitalize! with ! should read like:
Capitalize only the first character within string ‘string’
What about this:
x = string[0,1]
x.capitalize!

Should this still capitalize only the first character within string
‘string’? I think the answer is obviously no. But your code is
essentially the same, without using the temporary variable x.

bw,
Peter


#12

Hi –

On Sat, 8 Apr 2006, Peter wrote:

Funny.
But thanks all.

It may be cumbersome but the alternative you describe would be worse
:slight_smile:

Ruby is pretty strict about left-to-right evaluation. This:

string[0,1]

means something: a one-character substring of string. What you do
with that substring – what messages you send it – is a completely
separate, subsequent transaction.

David


David A. Black (removed_email_address@domain.invalid)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

“Ruby for Rails” coming in PDF April 15, and in paper May 1!
http://www.manning.com/black


#13

Speaking of alternatives, here is how you also could do it:
string[0] = string[0].chr.upcase

2006/4/8, removed_email_address@domain.invalid removed_email_address@domain.invalid:


#14

On 4/9/06, Peter removed_email_address@domain.invalid wrote:

string[0] = string[0].chr.capitalize

Thanx All


Posted via http://www.ruby-forum.com/.

I am glad you like it, but why?


Deux choses sont infinies : l’univers et la bêtise humaine ; en ce qui
concerne l’univers, je n’en ai pas acquis la certitude absolue.

  • Albert Einstein

#15

Jeppe J. wrote:

string[0] = string[0].chr.upcase

Yep this is the one.
I think [0] is more natural.
I don’t need a range.

So with a slight change:
string = “this is a String”
string[0] = string[0].chr.capitalize

Thanx All