Characters replacement in a string in c#
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16 aprilie 2012 05:14
I have a string and i want to replace its every character with different one. i have a predefined pattern according to which i have to make the conversion.
'a' must be replaced with 'y', 'b' must b replaced by 'd', 'y' must be replaced by 'a' and so on...
according to my conversion if a string contains 'aby' then it must be converted to 'yda'.
How to do that ?
Toate mesajele
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16 aprilie 2012 06:12
Take a Dictionary<char, char> where you strore all the character mapping. Then, whenver you want to convert a string, use this dictionary to replace characters. For example,
class Encrypter { Dictionary<char, char> mappings = new Dictionary<char, char>(); public Encrypter() { mappings.Add('a', 'y'); mappings.Add('b', 'd'); mappings.Add('c', 'r'); mappings.Add('r', 'i'); mappings.Add('k', 'l'); mappings.Add('e', 's'); mappings.Add('i', 'm'); mappings.Add('t', 'o'); } public string ConvertString(string input) { string output = String.Empty; foreach (var item in input) { output += mappings[item]; } return output; } }Now, you can convert your string like below,
Encrypter e = new Encrypter(); //-- create instance of above class string encryptedString = e.ConvertString("cricket"); //-- Convert the string Console.WriteLine(encryptedString);I hope this helps.Please mark this post as answer if it solved your problem. Happy Programming!
- Propus ca răspuns de Kris Anderson 17 aprilie 2012 01:50
- Marcat ca răspuns de Rumman Siddiqui 17 aprilie 2012 06:13
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16 aprilie 2012 07:37
Here you go:
class Program { static void Main(string[] args) { Console.WriteLine("Input string"); string input = Console.ReadLine(); string newString = ""; foreach (char letter in input) { newString += ConvertedChar(letter); } Console.WriteLine(newString); } private static string ConvertedChar(char letter) { switch (letter) { case 'a': return "y"; case 'b': return "d"; case 'y': return "a"; default: return "-"; } } }Noam B.
Do not Forget to Vote as Answer/Helpful, please. It encourages us to help you... -
16 aprilie 2012 07:41
You can add this following class in your code.
here, Class Have Function "Encrypt", "Decrypt" to encode & decode your char or string
public class MySecurity { public static string Encrypt(string str) { string strReturn = ""; char[] chArray = str.Trim().ToCharArray(); Random rnd = new Random(); for (int i = 0; i < chArray.Length; i++) { strReturn = strReturn + rnd.Next(1, 9999).ToString() + GetEncryptChar(chArray[i]) + "¶"; } return strReturn.TrimEnd('¶'); } private static char GetEncryptChar(char chr) { char chrReturn; switch (chr) { case 'a': chrReturn = 'd'; break; case 'b': chrReturn = 'e'; break; case 'c': chrReturn = 'f'; break; case 'd': chrReturn = 'g'; break; case 'e': chrReturn = 'h'; break; case 'f': chrReturn = 'i'; break; case 'g': chrReturn = 'j'; break; case 'h': chrReturn = 'k'; break; case 'i': chrReturn = 'l'; break; case 'j': chrReturn = 'm'; break; case 'k': chrReturn = 'n'; break; case 'l': chrReturn = 'o'; break; case 'm': chrReturn = 'p'; break; case 'n': chrReturn = 'q'; break; case 'o': chrReturn = 'r'; break; case 'p': chrReturn = 's'; break; case 'q': chrReturn = 't'; break; case 'r': chrReturn = 'u'; break; case 's': chrReturn = 'v'; break; case 't': chrReturn = 'w'; break; case 'u': chrReturn = 'x'; break; case 'v': chrReturn = 'y'; break; case 'w': chrReturn = 'z'; break; case 'x': chrReturn = 'a'; break; case 'y': chrReturn = 'b'; break; case 'z': chrReturn = 'c'; break; case 'A': chrReturn = 'D'; break; case 'B': chrReturn = 'E'; break; case 'C': chrReturn = 'F'; break; case 'D': chrReturn = 'G'; break; case 'E': chrReturn = 'H'; break; case 'F': chrReturn = 'I'; break; case 'G': chrReturn = 'J'; break; case 'H': chrReturn = 'K'; break; case 'I': chrReturn = 'L'; break; case 'J': chrReturn = 'M'; break; case 'K': chrReturn = 'N'; break; case 'L': chrReturn = 'O'; break; case 'M': chrReturn = 'P'; break; case 'N': chrReturn = 'Q'; break; case 'O': chrReturn = 'R'; break; case 'P': chrReturn = 'S'; break; case 'Q': chrReturn = 'T'; break; case 'R': chrReturn = 'U'; break; case 'S': chrReturn = 'V'; break; case 'T': chrReturn = 'W'; break; case 'U': chrReturn = 'X'; break; case 'V': chrReturn = 'Y'; break; case 'W': chrReturn = 'Z'; break; case 'X': chrReturn = 'A'; break; case 'Y': chrReturn = 'B'; break; case 'Z': chrReturn = 'C'; break; case '1': chrReturn = '4'; break; case '2': chrReturn = '5'; break; case '3': chrReturn = '6'; break; case '4': chrReturn = '7'; break; case '5': chrReturn = '8'; break; case '6': chrReturn = '9'; break; case '7': chrReturn = '0'; break; case '8': chrReturn = '1'; break; case '9': chrReturn = '2'; break; case '0': chrReturn = '3'; break; default: chrReturn = chr; break; } return chrReturn; } private static char GetDecryptChar(char chr) { char chrReturn; switch (chr) { case 'a': chrReturn = 'x'; break; case 'b': chrReturn = 'y'; break; case 'c': chrReturn = 'z'; break; case 'd': chrReturn = 'a'; break; case 'e': chrReturn = 'b'; break; case 'f': chrReturn = 'c'; break; case 'g': chrReturn = 'd'; break; case 'h': chrReturn = 'e'; break; case 'i': chrReturn = 'f'; break; case 'j': chrReturn = 'g'; break; case 'k': chrReturn = 'h'; break; case 'l': chrReturn = 'i'; break; case 'm': chrReturn = 'j'; break; case 'n': chrReturn = 'k'; break; case 'o': chrReturn = 'l'; break; case 'p': chrReturn = 'm'; break; case 'q': chrReturn = 'n'; break; case 'r': chrReturn = 'o'; break; case 's': chrReturn = 'p'; break; case 't': chrReturn = 'q'; break; case 'u': chrReturn = 'r'; break; case 'v': chrReturn = 's'; break; case 'w': chrReturn = 't'; break; case 'x': chrReturn = 'u'; break; case 'y': chrReturn = 'v'; break; case 'z': chrReturn = 'w'; break; case 'A': chrReturn = 'X'; break; case 'B': chrReturn = 'Y'; break; case 'C': chrReturn = 'Z'; break; case 'D': chrReturn = 'A'; break; case 'E': chrReturn = 'B'; break; case 'F': chrReturn = 'C'; break; case 'G': chrReturn = 'D'; break; case 'H': chrReturn = 'E'; break; case 'I': chrReturn = 'F'; break; case 'J': chrReturn = 'G'; break; case 'K': chrReturn = 'H'; break; case 'L': chrReturn = 'I'; break; case 'M': chrReturn = 'J'; break; case 'N': chrReturn = 'K'; break; case 'O': chrReturn = 'L'; break; case 'P': chrReturn = 'M'; break; case 'Q': chrReturn = 'N'; break; case 'R': chrReturn = 'O'; break; case 'S': chrReturn = 'P'; break; case 'T': chrReturn = 'Q'; break; case 'U': chrReturn = 'R'; break; case 'V': chrReturn = 'S'; break; case 'W': chrReturn = 'T'; break; case 'X': chrReturn = 'U'; break; case 'Y': chrReturn = 'V'; break; case 'Z': chrReturn = 'W'; break; case '1': chrReturn = '8'; break; case '2': chrReturn = '9'; break; case '3': chrReturn = '0'; break; case '4': chrReturn = '1'; break; case '5': chrReturn = '2'; break; case '6': chrReturn = '3'; break; case '7': chrReturn = '4'; break; case '8': chrReturn = '5'; break; case '9': chrReturn = '6'; break; case '0': chrReturn = '7'; break; default: chrReturn = chr; break; } return chrReturn; } public static string Decrypt(string str) { string strReturn = ""; string[] strArray = str.Split('¶'); for (int i = 0; i < strArray.Length; i++) { strReturn = strReturn + GetDecryptChar(Convert.ToChar(strArray[i].Substring(strArray[i].Length - 1))); } return strReturn; } }
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16 aprilie 2012 08:27
If you are also interested in a short LINQ solution, then try this:
string old_characters = "aby"; // ... and so on -- the characters to be replaced
string new_characters = "yda"; // ... and so on -- the new characters
string sample = "test: ybbabay";
string result =
new string( ( from c in sample
let k = old_characters.IndexOf( c )
select k < 0 ? c : new_characters[k] ).ToArray() );
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16 aprilie 2012 17:37
Please check following link, it may be useful to you.
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16 aprilie 2012 19:29Pretty much every answer here has uses basic string concatenation to add each character to a temp string before returning it. This is terrible for performance. You should use a StringBuilder to build the string and then use .ToString on it when you want the final result. This will save a LOT of memory, and also a decent amount of processor time, especially if the strings aren't really small.
