Very often when migrating traditional windows application written in VB6, we may come across the inbuilt functions which were available in VB6, but not available in C#. One such function is Mid Function.

Visual Basic has a Mid function and a Mid statement. These elements both operate on a specified number of characters in a string, but the Mid function returns the characters while the Mid statement replaces the characters.

Mid Function has following parameters

Mid Statement

Replaces a specified number of characters in a String variable with characters from another string.
Mid Statement has the following parameters.

StringExpression

Required. String expression that replaces part of Target.

Here is the C# version for the same code.

  1. /// <param name="newChar"> Character to be replaced.</param>
  3. /// <returns></returns>
  5. public static string Mid(string input, int index, char newChar)
  7. {
  9. if (input == null)
  11. {
  13. throw new ArgumentNullException("input");
  15. }
  17. char[] chars = input.ToCharArray();
  19. chars[index-1] = newChar;
  21. return new string(chars);
  23. }
  25. /// <summary>
  27. /// This is equivalent to Mid Function in VB6
  29. /// </summary>
  31. /// <param name="s"> String to Check.</param>
  33. /// <param name="a">Position of Character</param>
  35. /// <param name="b">Length </param>
  37. /// <returns></returns>
  39. public static string Mid(string s, int a, int b)
  41. {
  43. string temp = s.Substring(a - 1, b);
  45. return temp;
  47. }
  49. }