Get a substring using 2 patterns in Dart?

Question

How can I pull out a string from two different patterns either side of the string I want: eg

 String s=  bg_img_pulloutthisstring@s_200

How can I pull out pulloutthisstring from s?

You should be very clear about what you want. What are the delimiters? Is it "bg_img_" and "@s_200" or just "_" and "@"? Can the delimiters occur inside the match? That is: Are you going for a maximal or minimal match in cases where there might be more than one? A RegExp can likely solve the problem in any case (and so can non-RegExp code), but it can only do one thing at a tie, so you should be careful to solve the correct problem. — lrn
– lrn, Commented Aug 7, 2020 at 16:57

julemand101 · Accepted Answer · 2020-08-07 12:11:13Z

1

The easiest is to use a Regular Expression and use a match group:

void main() {
  const s = 'bg_img_pulloutthisstring@s_200';
  print(RegExp(r'bg_img_(.*)@s_200').firstMatch(s).group(1)); // pulloutthisstring
}

answered Aug 7, 2020 at 12:11

julemand101

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