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How to pass arrays using ref and out parameter

Anupam Mishra 1432 09-Feb-2016
Hi Everyone,
I am working on arrays and i need to pass arrays using ref and out parameter in a function.my function are given below:
static void FillArray(ref int[] arr)
{
.......
}
Please can anyone give me a solution in both cases(ref and out parameter).
c# c#  asp.net 
Updated on 09-Feb-2016
Anupam Mishra

Anupam Mishra

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1 Answers

Manoj Bhatt

Manoj Bhatt

09-Feb-2016
ref parameter:  A ref parameter of an array type must be definitely assigned by the caller. Therefore, there is no need to be definitely assigned by the callee. 
out parameter:  An out parameter of an array type must be assigned before it is used; that is, it must be assigned by the callee.
Here we demonstrate using your method for both cases:
  // For out parameter
    class TestOut
    {
        static void FillArray(out int[] arr)
        {
            // Initialize the array:
            arr = new int[5] { 10,20,30,40,50 };
        }
       public static void MainE()
        {
            // Initialization is not required 
            int[] theArray; 
            // Pass the array to the callee using out parameter:
            FillArray(out theArray);
            // Display the array elements:
            System.Console.WriteLine("Array elements are:");
            for (int i = 0; i < theArray.Length; i++)
            {
                System.Console.Write(theArray[i] +" ");
            }
           }
    }
    // For Ref Parameter
    classTestRef
    {
        staticvoid FillArray(refint[] arr)
        {
            // Create the array on demand:
            if (arr == null)
            {
                arr = newint[10];
            }
            // Fill the array:
            arr[0] = 1000;
            arr[4] = 5000;
        }
        staticvoid Main()
        {
            // Calling Out parameter static method
            TestOut.MainE();
            // Initialize the array:
            int[] theArray = { 10,20,30,40,50 };
            // Pass the array using ref:            
            FillArray(ref theArray);
            // Display the updated array:
            System.Console.WriteLine("Array elements are:");
            for (int i = 0; i < theArray.Length; i++)
            {
                System.Console.Write(theArray[i] +" ");
            }           
            System.Console.ReadKey();
        }
    }

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