Substring add free space after each 4 character

Question

public static string ToIbanFormat(this string value)
        {
            if (value.Length > 16)
            {
                string iban = value.Substring(0, 4) + " " + 
                              value.Substring(4, 4) + " " + 
                              value.Substring(8, 4) + " " + 
                              value.Substring(12, 4) + " " +
                              value.Substring(16);

                return iban;
            }

            return value;
        }

can I somehow do it dynamically if there is more characters that I can use spaces also after each 4 char.

For example my code will not work for: GR16 0110 1250 0000 0001 2300 695

and I do n't want to add another if. Can I do this dynamically to check the length and then substring it?

http://stackoverflow.com/questions/9932096/add-separator-to-string-at-every-n-characters — Tim Schmelter, Nov 26 '14 at 11:09

mihai · Answer 1 · 2014-11-26T11:27:22.557

3

You can replace every 4th character with that character plus a space:

return value
    .Select((x, i) => (i + 1) % 4 == 0 ? x + " " : x.ToString())
    .Aggregate((x, y) => x + y);

edited Nov 26 '14 at 11:27

answered Nov 26 '14 at 11:12

mihai

4,592
3
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42

The good thing about this is that you can change `(i + 1) % 4 == 0` into `(i + 1) % 4 == 0 && x != ' '` if you want to not insert the space if `x` is already a space, `' '`. The question is unclear, but maybe the asker wanted that. – Jeppe Stig Nielsen Nov 26 '14 at 11:39
(Edited!) With `Concat` your answer becomes `return string.Concat(value.Select((x, i) => (i + 1) % 4 == 0 ? x + " " : x.ToString()));`. – Jeppe Stig Nielsen Nov 26 '14 at 11:42

score 3 · Accepted Answer · answered Nov 26 '14 at 11:13

3

Regex.Replace(value, ".{4}", "$0 ").Trim() should do the trick.

answered Nov 26 '14 at 11:13

Anonymous

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133

score 1 · Answer 3 · answered Nov 26 '14 at 11:15

This works:

var text = "GR1601101250000000012300695";

var result = String.Join(" ",
    text
        .ToCharArray()
        .Buffer(4)
        .Select(x => new string(x.ToArray())));

But Bufferrequires that you NuGet "Ix-Main" from the Microsoft Reactive Framework Team.

Personally I like the RegEx approach, but I think this is more readable and hence more maintainable.

score 1 · Answer 4 · answered Nov 26 '14 at 11:16

1

String str = "GR1601101250000000012300695";
StringBuilder result=new StringBuilder();
for(int i=0;i<str.Length;i++)
{
  if ((i+1) % 4 == 0)
    result.Append(str[i] + " ");
  else
    result.Append(str[i]);
}

result = GR16 0110 1250 0000 0001 2300 695

answered Nov 26 '14 at 11:16

Sudhakar Tillapudi

25,935
5
37
67

Substring add free space after each 4 character

4 Answers4