Javascript regular expression to sanitize string with pipes

Question

I need a little help in trying to sanitize a string. I have written a regular expression that is pretty close to giving me the results I want but I just can't quite get it right. The string I'm receiving is in this format. ||a|assa||asss||ssss The pipe character are basically placeholders to what would have been a separator for text. However, I'm trying to end up with something that would look like this. |a|b|c|d in other words I'm just trying to remove consecutive pipes. I have put together a little example to illustrate what I have attempted and keep failing miserably.

const str1 = "||a||jump|fences||in the street";
const str2 = "im a wolf";
const hasPipe = /\|{1}\+/;//if the | is consecutevely repeated more than once than deleted.

console.log(hasPipe.test(str1));
console.log(str1.replace(hasPipe, ""))
console.log(hasPipe.test(str2));

The expected result to the above code should simply be. |a|jump|fences|in the street" Can someone please point me in the right direction or point my silly mistake.

You're completely misunderstanding regex. To repeat, you just want +. — SLaks
– SLaks, Commented May 25, 2018 at 17:46
I'm pretty certain I've tried that variation and was not able to get the results correctly. I'll give it another shot. so should it be these ? /\|\+/ because that does not seem to work? — Miguel
– Miguel, Commented May 25, 2018 at 17:47
Why are you escaping the +? Read the documentation and learn how regex works. — SLaks
– SLaks, Commented May 25, 2018 at 17:55

l'L'l · Accepted Answer · 2018-05-25 18:05:46Z

2

Given your test string const str1 = "||a||jump|fences||in the street"; you want to replace multiple occurrences of pipe | with a single pipe.

There are a couple of ways to match a non-empty sequence:
+ = match 1 or more of the previous expression
{n,m} = match at least n but not more than m occurrences.
{n,} = match at least n and unlimited times.

Simple:

str1.replace(/\|+/g, "|")
"|a|jump|fences|in the street"

Matches one or more pipes and replaces with a single pipe. This replaces a single pipe with a pipe.

More exact:

str1.replace(/\|{2,}/g, "|")
"|a|jump|fences|in the street"

Matches two or more (because there is no max after the comma) pipes and replaces with a single pipe. This does not bother replacing a single pipe with another single pipe.

There are also a couple of ways to match exactly two pipes, if you'll never have a run of 3 or more:

str1.replace(/\|\|/, "|");
str1.replace(/\|{2}/, "|");

edited May 25, 2018 at 18:05

l'L'l

47.5k12 gold badges102 silver badges154 bronze badges

answered May 25, 2018 at 17:57

Stephen P

14.9k2 gold badges50 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Miguel Over a year ago

Thank you so much Stephen for the explanation. I have been added for a few hours now and I could not grasp why it was not working. I'm sincerely humbled and appreciative.

zzxyz · Accepted Answer · 2018-05-25 17:56:09Z

2

Not much to it:
\|\|+ replace with |

https://regex101.com/r/vvkrI0/1/

answered May 25, 2018 at 17:56

zzxyz

3,0001 gold badge20 silver badges32 bronze badges

Comments

RToyo · Accepted Answer · 2018-05-25 17:58:38Z

2

You can use the + to find all the locations that have 1 or more pipes in a row, and replace them all with a single pipe. Your regex would simply be:

/\|+/g

Here is an example, with a variable number of pipes:

const str1 = "||a|||jump|fences||||in the street";
var filtered_str1 = str1.replace(/\|+/g,"|")
console.log(filtered_str1);

answered May 25, 2018 at 17:58

RToyo

2,8771 gold badge18 silver badges25 bronze badges

Comments

l'L'l · Accepted Answer · 2018-05-25 17:57:35Z

1

You could substitute consective pipe characters like this:

const pat = /\|{2,}/gm;
const str = `||a|||jump|fences||in the street`;
const sub = `|`;

const res = str.replace(pat, sub);
console.log('result: ', res);

Result:

|a|jump|fences|in the street

answered May 25, 2018 at 17:57

l'L'l

47.5k12 gold badges102 silver badges154 bronze badges

Collectives™ on Stack Overflow

Javascript regular expression to sanitize string with pipes

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related