extracting sustrings from a string to array

Question

Hi

I want to extract sustrings from a string and want to store in an array.
The string is dynamic it will change but the criteria to extract substring is same.
say for example a string str="something is [!better] than [!nothing]"
so i need to extract [!better] and [!nothing] from the string and store it in a string array, the string is dynamic it changes but i need to extract data between [ and ] including both the square brackets.
If anybody can send any sample code, I will be very thankfull.
Thanks

Ansari

Alan · Answer

OK here's a revised version which can deal with any number of substrings: using System; using System.Collections.Generic; class Program { static void Main() { List list = new List (); string str = something is [!better] than [!nothing]; list.AddRange(ExtractSubstrings(str)); string str2 = something [!is] better [!than] [!nothing]; list.AddRange(ExtractSubstrings(str2)); string[] results = list.ToArray(); // check it worked foreach(string result in results) { Console.WriteLine(result); } Console.ReadKey(); } static List ExtractSubstrings(string str) { if (str == null) return null; List results = new List (); if (str == ) return results; // empty list int index1 = 0 index2 = 0; bool finished = false; do { index1 = str.IndexOf([ index2); if (index1 == - 1) { finished = true; } else { index2 = str.IndexOf(] index1); if (index2 == - 1) { finished = true; } else { results.Add(str.Substring(index1 index2 - index1 + 1)); } } } while(!finished); return results; } }

wajid ansari · Answer

Thanks a lot alan. your code is very helpfull.

wajid ansari · Answer

Hi Alan Thanks for your quick reply. I appreciate it your help. One more updation in the code please Your code seems to work to extract two substrings but if the string is something [!is] better [!than] [!nothing] then I need to extract three substrings but it is extracting [!is] and [!than] can you please update your code to get any number of substrings because the string that I am passing will have any number of substrings. Thanks again Hope you will reply soon. Thanks Ansari

Alan · Answer

You could use regular expressions for this but I thought I'd do it using ordinary string parsing (including full error checking) which should be quicker: using System; using System.Collections.Generic; class Program { static void Main() { List list = new List (); string str = something is [!better] than [!nothing]; string sub1 sub2; ExtractSubstrings(str out sub1 out sub2); list.Add(sub1); list.Add(sub2); string str2 = nothing is [!worse] than [!something]; string sub3 sub4; ExtractSubstrings(str2 out sub3 out sub4); list.Add(sub3); list.Add(sub4); string[] results = list.ToArray(); // check it worked foreach(string result in results) { Console.WriteLine(result); } Console.ReadKey(); } static void ExtractSubstrings(string str out string sub1 out string sub2) { if (String.IsNullOrEmpty(str)) { sub1 = sub2 = str; return; } int index1 = str.IndexOf([); if (index1 == - 1) { sub1 = sub2 = ; return; } int index2 = str.IndexOf(] index1); if (index2 == - 1) { sub1 = sub2 = ; return; } sub1 = str.Substring(index1 index2 - index1 + 1); int index3 = str.IndexOf([ index2); if (index3 == - 1) { sub2 = ; return; } int index4 = str.IndexOf(] index3); if (index4 == - 1) { sub2 = ; return; } sub2 = str.Substring(index3 index4 - index3 + 1); } }