forum

Home / DeveloperSection / Forums / difference between ref and out keywords

Ask Question

difference between ref and out keywords

Anupam Mishra 1270 01-Feb-2016
Hi Everyone,
 I want to know what is difference between ref and out keywords.Please can anyone give me a exact situation.
thank you.
c# c#  .net 
Updated on 01-Feb-2016
Anupam Mishra

Anupam Mishra

Follow

Can you answer this question?

Answer

1 Answers

Anupam Mishra

Anupam Mishra

01-Feb-2016

If we want to pass a variable as ref parameter we need to initialize it before we pass it as ref parameter to method. Ref keyword will pass parameter as a reference this means when the value of 
parameter is changed in called method it get reflected in calling method also.

i = 10;
public static void RefTest(ref int val1)
{
   val1 += 10;
}
Output : 20
If we want to pass a variable as out parameter we don’t need to initialize it before we pass it as out parameter to method. Out keyword also will pass parameter as a reference but here out parameter must be initialized in called method before it return value to calling method.

int i,j; // No need to initialize variable
OutTest(out i, out j);
public static int OutTest(out int val1, out int val2)
{
  val1 = 5;
  val2 = 10;
  return 0;
}

Liked By