How to replace captured groups only

Question

I have HTML code before and after the string  name  quot some text 0 some text quot   I would like to replace the 0 with something like    NEW ID  So I made a simple regex      name  quot  w   d   w  quot     But I don t see how to replace exclusively the captured block  Is there a way to replace a captured result like   1  with some other string   The result would be   name  quot some text  NEW ID  some text quot

User · Answer

A little improvement to Matthew s answer could be a lookahead instead of the last capturing group    replace    w    d      w       1 NEW ID       Or you could split on the decimal and join with your new id like this    split   d    join   NEW ID       Example Benchmark here  https   codepen io jogai full oyNXBX

User · Answer

Now that Javascript has lookbehind  as of ES2018   on newer environments  you can avoid groups entirely in situations like these  Rather  lookbehind for what comes before the group you were capturing  and lookahead for what comes after  and replace with just  NEW ID    x000D   x000D  const str    name  some text 0 some text    console log    str replace     lt  name   w   d     w        NEW ID       x000D   x000D   x000D   With this method  the full match is only the part that needs to be replaced      lt  name  quot  w   - Lookbehind for name  quot   followed by word characters  luckily  lookbehinds do not have to be fixed width in Javascript    d  - Match one or more digits - the only part of the pattern not in a lookaround  the only part of the string that will be in the resulting match     w  quot   - Lookahead for word characters followed by  quot     Keep in mind that lookbehind is pretty new  It works in modern versions of V8  including Chrome  Opera  and Node   but not in most other environments  at least not yet  So while you can reliably use lookbehind in Node and in your own browser  if it runs on a modern version of V8   it s not yet sufficiently supported by random clients  like on a public website

User · Answer

A simplier option is to just capture the digits and replace them    x000D   x000D  const name    preceding text 0 following text   x000D  const matcher      d     x000D   x000D     Replace with whatever you would like x000D  const newName   name replace matcher   NEW STUFF    x000D  console log  Full replace   newName   x000D   x000D     Perform work on the match and replace using a function x000D     In this case increment it using an arrow function x000D  const incrementedName   name replace matcher   match    gt    match   x000D  console log  Increment   incrementedName   x000D   x000D   x000D    Resources   https   developer mozilla org en-US docs Web JavaScript Reference Global Objects String replace

User · Answer

With two capturing groups would have been also possible  I would have also included two dashes  as additional left and right boundaries  before and after the digits  and the modified expression would have looked like      name       d                x000D   x000D  const regex       name       d             g  x000D  const str    some data before name  some text 0 some text  and then some data after   x000D  const subst     1 NEW ID  2   x000D  const result   str replace regex  subst   x000D  console log result   x000D   x000D   x000D         If you wish to explore simplify modify the expression  it s been   explained on the top right panel of   regex101 com  If you d like  you   can also watch in this   link  how it would match   against some sample inputs      RegEx Circuit  jex im visualizes regular expressions

User · Answer

A solution is to add captures for the preceding and following text   str replace     name   w    d    w          1 NEW ID  3

[javascript] How to replace captured groups only?

Examples related to javascript

Examples related to regex