How to remove empty lines from a string?

Maim · Jan 19, 2005

I have a string object as follows
"abc

def

ghi

jkl

mno"

I would like to transform it into
"abc
def
ghi
jkl
mno"

I'm not familiar with regular expression pattern matching so I'm asking here.

I tried something like

Code:

text = text.split(/^\r\n/).join('');

but that doesn't do anything.

Any help is appreciated.

-----------------------------------
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rich Cook

trollacious · Jan 19, 2005

To get rid of all blank lines, no matter how many there are in a row (2, 3, 4, etc.), you can use (I know it's not regular expressions):

while (text.indexOf('\n\n')
{
text=text.replace('\n\n', '\n');
}

Lee

tsdragon · Jan 19, 2005

Is there a chance that there will be blank spaces on the lines as well? Whether or not, this should work:

Code:

var myRe = /^[ \r\n]+$/gi;
theString = theString.replace(myRe,"");

I put the space, carriage-return and line-feed in a character class just in case you get a string that uses one, but not the other (i.e unix or mac).

Tracy Dryden

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard. [dragon]

trollacious · Jan 19, 2005

I missed a final > -1) at the end of the first line:

while (text.indexOf('\n\n') > -1)
{
text=text.replace('\n\n', '\n');
}

Maim · Jan 19, 2005

trollacious: Thanks for the suggestion, however '\n\n' isn't enough, using '\r\n\r\n' and replacing with '\r\n' does the job

tsdragon: No the lines I want removed are completely empty, if there's a space, then leave it. Uh, and the code didn't seem to work. Maybe because no spaces?

Thanks guys

-----------------------------------
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rich Cook

tsdragon · Jan 19, 2005

Of course is doesn't work, and I'm an idiot. JS doesn't have "multiline matching" like perl does. MSDN says the ^ and $ match at the end of the line or string. I'm assuming in this case they only match at the end of the string, so of course unless you have nothing but space, CR and LF it won't match. Take out the ^ and $ and it works. Oh, you might want to replace CR and LF with space instead of nothing. Run my example and you'll see why.
Here's the code I tested with:

Code:

<HTML>
<HEAD>
<META NAME="GENERATOR" Content="Microsoft Visual Studio 6.0">
<TITLE></TITLE>
</HEAD>
<BODY>
<b>before replacing:</b>
<hr>
<pre id=o1></pre>
<hr>
<br>
<b>after replacing:</b>
<hr>
<pre id=o2></pre>
<hr>
<br>
</BODY>
<script language="JavaScript">
var aStr = "Tracy\n\n\nDryden\n  \n\rtsdragon\n \r\nme";
var myre = /[\r\n]+/gi;
var bStr = aStr.replace(myre,"");
document.getElementById('o1').innerText = aStr;
document.getElementById('o2').innerText = bStr;
</script>
</HTML>

See my new posting under "Important Lesson" here too. It's very relevant to this thread.

Tracy Dryden

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard. [dragon]

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How to remove empty lines from a string?

Maim

Programmer

trollacious

Programmer

tsdragon

Programmer

trollacious

Programmer

Maim

Programmer

tsdragon

Programmer

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