Regular Expression help: multi-line mode

[Wayne]

I wish to remove the last newline (if any) from a string.
This is where I started:

var text = "hello\n";
text = text.replace( /^(.*)\n?$/, "$1" );

This seems to work, but not if the test has embedded newlines:
text = "hello\ngood-bye\n";

I've tried a few variations but no luck so far.
(I worked around the problem by testing if the
last character == '\n' and if so use text.slice(0,-1)
to remove it.)

Can someone provide me the proper regex for this?
Thanks!

-Wayne

[Martin Honnen]

Wayne wrote:

I wish to remove the last newline (if any) from a string.

The do
string = string.replace(/\n$/, '');
--

Martin Honnen
http://JavaScript.FAQTs.com/

[Anthony Levensalor]

Wayne said:

Can someone provide me the proper regex for this?
Thanks!

-Wayne

Wayne,

I extrapolated it out to a separate call, and it worked for me.

alert(str.replace("\n"), "$1");

~A!

--
Anthony Levensalor
an*****@mypetprogrammer.com

Only two things are infinite, the universe and human stupidity,
and I'm not sure about the former. - Albert Einstein

[Evertjan.]

Martin Honnen wrote on 29 dec 2007 in comp.lang.javascript:

Wayne wrote:

>I wish to remove the last newline (if any) from a string.

The do
string = string.replace(/\n$/, '');

Non regex variation:

var temp = str.split('\n');
if (!temp.pop()) str = temp.join('\n');

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Evertjan.]

Anthony Levensalor wrote on 29 dec 2007 in comp.lang.javascript:

Wayne said:

>Can someone provide me the proper regex for this?
Thanks!

-Wayne

Wayne,

I extrapolated it out to a separate call, and it worked for me.

alert(str.replace("\n"), "$1");

I am sure you did not test that!

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Anthony Levensalor]

Evertjan. said:
[snip]

I am sure you did not test that!

I did, and it removed the newlines. Looking at it right now, though, I
see an obvious parens issue, how the hell did that even happen? Well,
even with the parens screwed up, it didn't toss any errors, and it
pulled out the newlines I stuck into a string.

--
Anthony Levensalor
an*****@mypetprogrammer.com

Only two things are infinite, the universe and human stupidity,
and I'm not sure about the former. - Albert Einstein

[Evertjan.]

Anthony Levensalor wrote on 29 dec 2007 in comp.lang.javascript:

Evertjan. said:
[snip]

>I am sure you did not test that!

I did, and it removed the newlines. Looking at it right now, though, I
see an obvious parens issue, how the hell did that even happen? Well,
even with the parens screwed up, it didn't toss any errors, and it
pulled out the newlines I stuck into a string.

But that was not the OQ.

Then even it did only work,
because of the strange compatibility of alert().

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Wayne]

Martin Honnen wrote:

Wayne wrote:

>I wish to remove the last newline (if any) from a string.

The do
string = string.replace(/\n$/, '');

So simple! That's what I get for working through the night,
on a weekend to boot! Thanks!

-Wayne

[Anthony Levensalor]

Evertjan. said:
[snip]

Then even it did only work,
because of the strange compatibility of alert().

I am 100% certain that's the only way it could have possibly worked with
so obvious a syntax error in it. I've been awake for three days and
haven't really left my desk, so if I missed a parenthesis issue, then I
missed it. Oh friggin' well.

~A!

--
Anthony Levensalor
an*****@mypetprogrammer.com

Only two things are infinite, the universe and human stupidity,
and I'm not sure about the former. - Albert Einstein

[Wayne]

Evertjan. wrote:

Martin Honnen wrote on 29 dec 2007 in comp.lang.javascript:

>Wayne wrote:

>>I wish to remove the last newline (if any) from a string.

The do
string = string.replace(/\n$/, '');

Non regex variation:

var temp = str.split('\n');
if (!temp.pop()) str = temp.join('\n');

Thanks! I know there must be a million ways,
but I am looking for one that is efficient.
It seems to me this would be slower (and take more
memory) than Martin's RegExp.

-Wayne

[Evertjan.]

Wayne wrote on 29 dec 2007 in comp.lang.javascript:

Evertjan. wrote:

>Martin Honnen wrote on 29 dec 2007 in comp.lang.javascript:

>>Wayne wrote:
I wish to remove the last newline (if any) from a string.
The do
string = string.replace(/\n$/, '');

Non regex variation:

var temp = str.split('\n');
if (!temp.pop()) str = temp.join('\n');

Thanks! I know there must be a million ways,
but I am looking for one that is efficient.
It seems to me this would be slower (and take more
memory) than Martin's RegExp.

I doubt that, in the case of the absence of the final \n,
as in the regex case the string is still duplicated twice,
once to an internal temporary location and then back
to the variable's string space. It is nearly as bad as string
concatenation.

So if speed were at a premium [which I doubt to be the case]
better do this:

if (/\n$/.test(string))
string = string.replace(/\n$/, '');

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)