正则表达式如何删除特定单词后的逗号

Question

I am currently trying to remove any commas after the specific word 'SUM(' and Before the last ')' by using a regex. In other words, I want to remove all the beginning and end commas inside of the function SUM(). I am using the javascript function replace to do this on a regex.

Here are examples to illustrate what I am trying to do after the replace function is called with a regex:

SUM(,,,,1,2,)  // result should be SUM(1,2)
SUM(,1,2,)    // result should be SUM(1,2)
SUM(,1,2,,,)  // result should be SUM(1,2)
SUM(,,,,1,34) // result should be SUM(1,34)
SUM(,,,,0,0,0) // result should be SUM(0,0,0)

Currently I have been trying this regex:

(^SUM\()\,|(\,+)\)$

But I only want to match on the commas that are after the word 'SUM(' and Before the last bracket ')'. Please can someone help me.

Answer 1

Use this pattern:

/(^SUM)\(,*(.*?),*\)/gm

And replace it with $1($2) .

Online Demo

Answer 2

Replace multiple commas with one comma, then fix up the beginning and end:

str . 
  replace(/,+/g, ',') . 
  replace(/\(,/, '(') . 
  replace(/,\)/, ')')

If you don't care about removing multiple commas between items, then

str . replace(/\(,+/g, '(') . replace(/,+\(/, '(')

You could use combine these into a single regexp as

 var str = "SUM(,1,2,,,)"; var result = str.replace(/(\\(),+|,+(\\))|(,),*/g, '$1$2$3') // ^^^^^^ MATCH (,,, // ^^^^^^ MATCH ,,,) // ^^^ MATCH commas between items document.write(result);