C# program to Determine if a string has all unique characters

• By following c# example we can verify the given string has the all unique characters or string has duplicate characters.

 class StringUnique  
   {  
     static bool uniqueCharacters(String str)  
     {  
       // If at any time we encounter 2   
       // same characters, return false   
       for (int i = 0; i < str.Length; i++)  
         for (int j = i + 1; j < str.Length; j++)  
           if (str[i] == str[j])  
             return false;  
       // If no duplicate characters   
       // encountered, return true   
       return true;  
     }  
     public static void Main()  
     {  
       string input = "abcdef";  
       if (uniqueCharacters(input) == true)  
         Console.WriteLine("The String " + input  
                  + " has all unique characters");  
       else  
         Console.WriteLine("The String " + input  
                  + " has duplicate characters");  
       Console.ReadLine();  
     }  
   }