title: How to create an array of non repeating random numbers
body: <p>I have a lottery application in C# which takes in the number of numbers to draw and also the maximum number to draw.I have coded up to creating an array holding the required random  numbers but I need them to be unique and am having trouble doing it.I would be very grateful if someone could give me some advice on this,Thanks</p>
  
  <p>Here is my code so far:</p>
  
  <pre><code>class Lottery
  
  {
  
    static int[] numberHolder; //array to be filled with numbers up to an 
                               //amount entered by the user eg 42 Max
  
    static int[] drawHolder;   //array to hold the each random number 
                               //drawn from the pool of numbers eg 7 numbers
  
      public Lottery() //Lottery class Constructor
      {
  
      }
  
  
      //method which takes in a number limit and amount of numbers to be drawn
      public String drawNumbers(int numLimit, int numAmount) 
      {
  
          Random RandomNumber = new Random();
  
          for (int i = 0; i &lt; numLimit ; i++) //loop to fill up numberHolder array
                                              // with predefined limit of numbers
  
          {
              numberHolder[i] = i++;
          }
  
          for (int i = 0; i &lt; numAmount; i++)
          {
  
  
              // code to pick unique random numbers no greater than numAmount 
              // and add them to the drawHolder[] array
              drawHolder[i] = RandomNumber.Next(1, numLimit);
  
          }
  
  
  
  
  
          //return the drawHolder array to String
          return null;
      }
  
  
  
  
  
  }
  </code></pre>