From: Ammar Ali <ammarabuali@...>
Date: 2010-10-28T18:53:34+09:00
Subject: Re: Word starts by a vowel

2010/10/28 Jesús Gabriel y Galán <jgabrielygalan@gmail.com>:
> On Thu, Oct 28, 2010 at 10:49 AM, Greg Ma <gregorylepacha@msn.com> wrote:
>> Hi,
>> How could I know if a word starts by a vowel?
>> I couln't find it online and I am a real nooby with regex...
>
> For this kind of task, you use a regex with a character class that
> contains the valid characters you want to check.
> You also need to anchor it at the start of the string to match only
> that position (or try to match only the first character):
>
> irb(main):001:0> "asdfsifnweif" =~ /\A[aeiou]/
> => 0
> irb(main):002:0> "vfvdasdfsifnweif" =~ /\A[aeiou]/
> => nil
> irb(main):005:0> "asdfsifnweif"[0,1] =~ /[aeiou]/
> => 0
> irb(main):006:0> "vfvdasdfsifnweif"[0,1] =~ /[aeiou]/
>
>
> Jesus.
>
>

I would like to add to Jesus' good advice that you can add a case
insensitive option (the letter i at the end) to match lower and upper
case vowels:

>> "Apple" =~ /^[aeiou]/i
=> 0
>> "apple" =~ /^[aeiou]/i
=> 0

Regards,
Ammar