CODEWITHSUNDEEP
javascriptregexstring
Ayan
Ayan

Reputation: 2380

Using regex, extract values from a string in javascript

Need to extract values from a string using regex(for perf reasons). Cases might be as follows:

  1. RED,100
  2. RED,"100"
  3. RED,"100,"
  4. RED,"100\"ABC\"200"

The resulting separated [label, value] array should be:

  1. ['RED','100']
  2. ['RED','100']
  3. ['RED','100,']
  4. ['RED','100"ABC"200']

I looked into solutions and a popular library even, just splits the entire string to get the values, e.g. 'RED,100'.split(/,/) might just do the thing.

But I was trying to make a regex with comma, which splits only if that comma is not enclosed within a quotes type value.

This isnt a standard CSV behaviour might be. But its very easy for end-user to enter values. enter label,value. Do whatever inside value, if thats surrounded by quotes. If you wanna contain quotes, use a backslash.

Any help is appreciated.

Upvotes: 0

Views: 2640

Answers (2)

Nina Scholz
Nina Scholz

Reputation: 386868

You could use String#match and take only the groups.

var array = ['RED,100', 'RED,"100"', 'RED,"100,"', 'RED,"100\"ABC\"200"'];

console.log(array.map(s => s.match(/^([^,]+),(.*)$/).slice(1)))

Upvotes: 1

anubhava
anubhava

Reputation: 786291

You can use this regex that takes care of escaped quotes in string:

/"[^"\\]*(?:\\.[^"\\]*)*"|[^,"]+/g

RegEx Explanation:

  • ": Match a literal opening quote
  • [^"\\]*: Match 0 or more of any character that is not \ and not a quote
  • (?:\\.[^"\\]*)*: Followed by escaped character and another non-quote, non-\. Match 0 or more of this combination to get through all escaped characters
  • ": Match closing quote
  • |: OR (alternation)
  • [^,"]+: Match 1+ of non-quote, non-comma string

RegEx Demo

const regex = /"[^"\\]*(?:\\.[^"\\]*)*"|[^,"]+/g;

const arr = [`RED,100`, `RED,"100"`, `RED,"100,"`,
`RED,"100\\"ABC\\"200"`];
let m;

for (var i = 0; i < arr.length; i++) {
  var str = arr[i];
  var result = [];
  while ((m = regex.exec(str)) !== null) {
    result.push(m[0]);
  }
  console.log("Input:", str, ":: Result =>", result);
}

Upvotes: 1

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