regex pattern needed to replace

Question

I am not too good at regular expressions so need some help from the community. any help is appreciated. I have a string as below

String str= "accountnumber,10000,accountname,Nachiket,balance,null,age,38"

I need a regex pattern to replace,10000, or,Nachiket, or,null, the string should look something similar

String str= "accountnumber,10000\naccountname,Nachiket\nbalance,null\nage,38"

This is my requirement. I have tried below pattern

String str=str.replace(",/[^a-z0-9-]/,",',/[^a-z0-9-]//n')

Thanks, Nachiket

Answer 1

It seems you are trying to group values like accountnumber,10000 and accountname,Nachiket etc. In that case, you can just search for two words and two comma patterns. Something like this:-

(.*?),(.*?),

Regex101 Sample - https://regex101.com/r/dEGs9c/1

And here is the JavaScript implementation

 let str = "accountnumber,10000,accountname,Nachiket,balance,null,age,38" let pattern = /(.*?),(.*?),/g let output = str.replace(pattern, (match)=> { // match will be => accountnumber,10000, => accountname,Nachiket, etc // use slice to remove the last character (comma) return match.slice(0, -1) + "\n" }) console.log(output)

Answer 2

Instead of using replace, you can match any char except a comma, followed by an optional part that matches a comma and again any char except a comma.

If you don't want to cross lines, you can use \n in the negated character class, or if you don't want to match spaces, you can use [^,\s]+

[^,\n]+(?:,[^,\n]+)?

Regex demo

 const regex = /[^,\n]+(?:,[^,\n]+)?/g; [ "accountnumber,10000,accountname,Nachiket,balance,null,age,38", "test1", "test2,test2", "test3,test3,test3" ].forEach(s => console.log(s.match(regex)));