Forum: Ruby Character classes use in Ruby

Can anyone help me by giving an explanatory example of each of the
below:

[:alnum:]

[:alpha:]

[:space:]

[:xdigit:]

[:punct:]

[:space:]

[:blank:]


Thanks

On 4 February 2013 20:26, Love U Ruby <lists@ruby-forum.com> wrote:

>
> [:punct:]
>
> [:space:]
>
> [:blank:]
>
>
> Thanks
>

http://lmgtfy.com/?q=%5B%3Aalnum%3A%5D+%20%5B%3Aal...


--
  Matthew Kerwin, B.Sc (CompSci) (Hons)
  http://matthew.kerwin.net.au/
  ABN: 59-013-727-651

  "You'll never find a programming language that frees
  you from the burden of clarifying your ideas." - xkcd

Hi,

aren't those names self-explanatory?

alnum = alphanumeric = a letter of any alphabet or a digit (a, Щ, 1, 
...)
space = spaces, tabs, newlines, ...
xdigit = hexadecimal digit (a-zA-Z0-9)

etc.

On 4 February 2013 20:29, Matthew Kerwin <matthew@kerwin.net.au> wrote:

>
>
> 
http://lmgtfy.com/?q=%5B%3Aalnum%3A%5D+%20%5B%3Aal...
>
>


I'm sorry, but I *just* answered another post where my solution detailed
the steps I used to *search Google for the answer*, and I know for a 
fact
that this answer can be resolved easily and instantly with a 2 second
search.

I will try to be more like Matz in future.  :$

--
  Matthew Kerwin, B.Sc (CompSci) (Hons)
  http://matthew.kerwin.net.au/
  ABN: 59-013-727-651

  "You'll never find a programming language that frees
  you from the burden of clarifying your ideas." - xkcd

my-ruby:
did you even try to google that list?
http://ruby-doc.org/core-1.9.3/Regexp.html


/[[:alnum:]]/ - Alphabetic and numeric character
/[[:alpha:]]/ - Alphabetic character
/[[:blank:]]/ - Space or tab
/[[:cntrl:]]/ - Control character
/[[:digit:]]/ - Digit
/[[:graph:]]/ - Non-blank character (excludes spaces, control 
characters, and similar)
/[[:lower:]]/ - Lowercase alphabetical character
/[[:print:]]/ - Like [:graph:], but includes the space character
/[[:punct:]]/ - Punctuation character
/[[:space:]]/ - Whitespace character ([:blank:], newline, carriage 
return, etc.)
/[[:upper:]]/ - Uppercase alphabetical
/[[:xdigit:]]/ - Digit allowed in a hexadecimal number (i.e., 0-9a-fA-F)

Hans Mackowiak wrote in post #1095104:
> my-ruby:
> did you even try to google that list?
> http://ruby-doc.org/core-1.9.3/Regexp.html
>
>
> /[[:alnum:]]/ - Alphabetic and numeric character
> /[[:alpha:]]/ - Alphabetic character
> /[[:blank:]]/ - Space or tab
> /[[:cntrl:]]/ - Control character
> /[[:digit:]]/ - Digit

I know their description - but would be good for me if I get a ruby tiny 
code to see their uses. Mainly how syntactically are they 
used,basically.

Thanks

On Mon, Feb 4, 2013 at 4:59 AM, Love U Ruby <lists@ruby-forum.com> 
wrote:
>> /[[:digit:]]/ - Digit
>
> I know their description - but would be good for me if I get a ruby tiny
> code to see their uses. Mainly how syntactically are they
> used,basically.

Read the page Hans pointed you to:

/[[:upper:]][[:lower:]]/.match("Hello") #=> #<MatchData "He">

digit for sample can match more than just plain 0-9

# U+06F2 is "EXTENDED ARABIC-INDIC DIGIT TWO"
/[[:digit:]]/.match("\u06F2")    #=> #<MatchData "\u{06F2}">

Hans Mackowiak wrote in post #1095110:
> digit for sample can match more than just plain 0-9
>
> # U+06F2 is "EXTENDED ARABIC-INDIC DIGIT TWO"
> /[[:digit:]]/.match("\u06F2")    #=> #<MatchData "\u{06F2}">


Any example for the others as I listed in my description?

Love U Ruby wrote in post #1095145:
> Hans Mackowiak wrote in post #1095110:
>> digit for sample can match more than just plain 0-9
>>
>> # U+06F2 is "EXTENDED ARABIC-INDIC DIGIT TWO"
>> /[[:digit:]]/.match("\u06F2")    #=> #<MatchData "\u{06F2}">
>
>
> Any example for the others as I listed in my description?

You now know the syntax, try them in IRB to discover their behaviour.

tamouse mailing lists wrote in post #1095109:
> On Mon, Feb 4, 2013 at 4:59 AM, Love U Ruby <lists@ruby-forum.com>
> wrote:
>>> /[[:digit:]]/ - Digit
>>
>> I know their description - but would be good for me if I get a ruby tiny
>> code to see their uses. Mainly how syntactically are they
>> used,basically.
>
> Read the page Hans pointed you to:
>
> /[[:upper:]][[:lower:]]/.match("Hello") #=> #<MatchData "He">


Okay! Could you explain how the matching here performed, to produce 
"#<MatchData "He">"

On Mon, Feb 4, 2013 at 7:46 AM, Love U Ruby <lists@ruby-forum.com> 
wrote:

> >
> > /[[:upper:]][[:lower:]]/.match("Hello") #=> #<MatchData "He">
>
>
> Okay! Could you explain how the matching here performed, to produce
> "#<MatchData "He">"
>
>
Could you at least at some point take 10 seconds and try to figure 
anything
out on your own? 99.9% of the fun of development is the excitement of
figuring something out. If all you are going to do every day is just
accomplish nothing then why bother with this path in life?

What possibly do you believe would produce that result? What about 
trying
with "hEllo" or "HELLO" or "hello" and see what comes back and see what 
you
can deduce from that. Then move on to something like "HeLlO" and see how 
it
works and what you can do to get multiple results and how to handle
multiple results.

You are missing so much of the enjoyment of the language by sitting 
there
and accomplishing absolutely nothing on your own.

On Mon, Feb 4, 2013 at 4:46 PM, Love U Ruby <lists@ruby-forum.com> 
wrote:
>>
>> /[[:upper:]][[:lower:]]/.match("Hello") #=> #<MatchData "He">
>
>
> Okay! Could you explain how the matching here performed, to produce
> "#<MatchData "He">"

There are tutorials on regular expressions out there on the web.
Nobody is going to go through the effort to write another one just for
you.

If you want a book, read "Mastering Regular Expressions".

Cheers

robert