Regular expressions: Find part of a string


#1

Hello Everyone,

I’m quite new to regular expressions, and I’m looking for a way to
find the first 3 letters in a string.

So let’s say I have the following string: “foobar”, I want to know
what the first three letters of this string is (in this case it’s
foo).

What is the regex to make this happen?

Thanks in advance.


#2

Jermaine wrote:

Thanks in advance.

p “foobar”[/…/]

simplest

p “foobar”[/\A…/]

\A anchors to beginning of string, which is

same as above for this regex

p “foobar”[/.{3,3}/]

accepts between 3 and 3 chars


#3

You could use regex for this, but if you just want the first three
characters, why not use the substring?

s=“foobar”
s[0,3]

Using regex, you could do something like:
“foobar”.match(/^…/).to_s

Matt


“… if you do follow your bliss you put yourself on a kind of
track that has been there all the while, waiting for you, and the life
that you ought to be living is the one you are living. When you can
see that, you begin to meet people who are in your field of bliss, and
they open doors to you. I say, follow your bliss and don’t be afraid,
and doors will open where you didn’t know they were going to be.” –
Joseph Campbell


#4

On Jun 4, 10:16 pm, “Matthew K. Williams” removed_email_address@domain.invalid wrote:

Hello Everyone,
Thanks in advance.
Great stuff. Very simple and concise, worked out great for me.
Thanks guys!


#5

In addition to other comments, you can go here and test your regular
expressions:

http://rubular.com/