I have a string that is like below.
,liger, unicorn, snipe,
how can I trim the leading and trailing comma in javascript?
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stackoverflow.com/questions/17720264/…– wattryCommented Nov 13, 2019 at 21:03
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5 Answers
because I believe everything can be solved with regex:
var str = ",liger, unicorn, snipe,"
var trim = str.replace(/(^,)|(,$)/g, "")
// trim now equals 'liger, unicorn, snipe'
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1@eyelidlessness Is there are joke related to your comment? I'm OutOfTheLoop– mohitmunCommented Mar 31, 2017 at 7:52
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12For @mohitmun (and anyone else who comes along). 'Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.' More info: blog.codinghorror.com/…– knickumCommented Jun 27, 2017 at 14:48
While cobbal's answer is the "best", in my opinion, I want to add one note: Depending on the formatting of your string and purpose of stripping leading and trailing commas, you may also want to watch out for whitespace.
var str = ',liger, unicorn, snipe,';
var trim = str.replace(/(^\s*,)|(,\s*$)/g, '');
Of course, with this application, the value of using regex over basic string methods is more obvious.
answered Mar 19, 2009 at 8:14
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2
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if anybody's interested about trimming spaces also, better use herostwist's answer below, its better.– SharkyCommented Mar 27, 2017 at 13:38
If you want to make sure you don't have any trailing commas or whitespace, you might want to use this regex.
var str = ' , , , foo, bar, ';
str = str.replace(/(^[,\s]+)|([,\s]+$)/g, '');
returns
"foo, bar"
answered Jul 28, 2014 at 14:35
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1For those wondering why this differs from eyelidlessness's, this solution strips spaces that are before the trailing comma or after the opening comma.– SamGoodyCommented Feb 2, 2015 at 10:02
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1It also handles multiple leading or trailing commas. For example,
,,,liger, unicorn, snipe,,,->liger, unicorn, snipe. Commented Mar 5, 2017 at 4:35 -
2It doesn't replace the commas coming after snipe. This is better
str.replace(/^[,\s]+|[,\s]+$/g, '').replace(/,[,\s]*,/g, ',');– cyonderCommented Apr 24, 2018 at 3:56 -
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Well you have moved the goalposts @cyonder, the question was "how can I trim the leading and trailing comma". In order to make your comment valid you have had to invent new problems. Commented Apr 28, 2018 at 16:43
Try this, since not everything can be solved by REs and even some things that can, shouldn't be :-)
<script type="text/javascript">
var str = ",liger, unicorn, snipe,";
if (str.substr(0,1) == ",") {
str = str.substring(1);
}
var len = str.length;
if (str.substr(len-1,1) == ",") {
str = str.substring(0,len-1);
}
alert (str);
</script>
answered Mar 19, 2009 at 7:27
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5Ask not what REs can do for you, but what you can do for REs! :)– cobbalCommented Mar 19, 2009 at 8:22
In ECMAScript 5 and above, you can now do a one-liner
',liger, unicorn, snipe,'.split(',').map(e => e.trim()).filter(e => e).join(', ')
