CODEWITHSUNDEEP
c#string
Izzy
Izzy

Reputation: 6866

Adding a prefix to start of string

I have a string being passed to me which can be between 1 and 6 characters long. Depending on the length of the string I need to add the appropriate prefix to the start of the string and return the appeneded string. So if I have something like the following passed to me

I want the return string to look like

I have come up with the following method 

public static string AddToStartOfString(string s)
{
    string value = string.Empty;

    switch (s.Length)
    {
      case 1:
         value = "X00000" + s;
         break;
      case 2:
         value = "X0000" + s;
         break;
      case 3:
         value = "X000" + s;
         break;
      case 4:
         value = "X00" + s;
         break;
      case 5:
         value = "X0" + s;
         break;
      case 6:
         value = "X" + s;
         break;
    }
    return value;
}

This works. But I need this to work in case in future more lengths are added. Is there a way where I can add the prefix even if the length of string is greater than 6 in the future

Upvotes: 1

Views: 12366

Answers (2)

DrNachtschatten
DrNachtschatten

Reputation: 412

had a similar problem recently, in your case i would do:

public static string Fill(string str, string prefix, int length)
{
    for(int i=str.Length; i<length; i++)
        str = "0" + str;

    return prefix + str;
}

Upvotes: -1

rems4e
rems4e

Reputation: 3172

You can do this:

public static string AddToStartOfString(string s, int digitCount = 6)
{
    return "X" + s.PadLeft(digitCount, '0');
}

Beware that an input string longer than the max number of digits, once transformed, will not be truncated and will be longer than for values in the correct range.

Upvotes: 4

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