CODEWITHSUNDEEP
javascriptregexreplace
user3871
user3871

Reputation: 12708

Replace match and ignore certain characters

I want to replace {r-group1} with "REPLACED" but leave the , where it is.

So, the string 

var string = "{r-group1, }foo bar"

should output: "REPLACED, foo bar"

Using a negative lookahead, I tried adding a preceding (?![,]) group to leave the comma alone:

var replaced = string.replace(^(?:(?![,]){r-group1\})+$, 'REPLACED');

But it returns the same string. There are no matches to replace.

The same goes for a preceding comma:

var string = "foo bar{r-, group1}"

This should output: "foo bar, REPLACED"

Upvotes: 0

Views: 1258

Answers (1)

The fourth bird
The fourth bird

Reputation: 163207

You could do the replacement without a lookahead. You could match the curly braces and the content that comes before and after it except a comma using a negated character class [^,}]+ and capture the comma with optional whitespace chars in a capturing group.

In the replacement use the capturing groups $1REPLACED$2

Credits to @Nick for the updated pattern.

{r-(,?\s*)[^,}]+(,?\s*)}

Regex demo

const regex = /{r-(,?\s*)[^,}]+(,?\s*)}/g;
const str = `{r-group1, }foo bar`;
const subst = `$1REPLACED$2`;
const result = str.replace(regex, subst);

console.log(result);

Upvotes: 2

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