Use of out parameter in C#

out


When out parameter is used inside the method declaration and call initialisation is not compulsory inside the main() method. It can be initialised inside the function declaration.

class Demo
{
 public int Change(out int i)
{
 i=5;
 return i * i;
 }
}
class Change
{
 static void main(string a[])
 {
 Demo d=new Demo();
 int a;
 int r= d.Change(out a);
 Console.WriteLine("r="+r);
 }
}

Output
r=25

Description:


In this program we are declaring a variable a inside the main method and passing it to the Change method.

d.Change(out a);

Then a receives value from i=5 inside the Change().
You have to use out in the method and also when calling the method.