Here we discuss the ref and out parameters in C#. They are basically parameters and we can use it in a different way.
ref parameter
It is used as a call by reference in C#. It is used both places; when we declare a method and when we call the method. The following example will explain how we use the ref parameter in C#. In this example we create a function (cube) and pass a ref parameter in it, now we look at the value before we call the function and after we call the function,
class TryRef
{
public void cube(ref int x)
{
x= x * x * x;
}
}
class Program
{
static void Main(string[] args)
{
TryRef tr = new TryRef();
int y = 5;
Console.WriteLine("The value of y before
the function call: " + y);
tr.cube(ref y);
Console.WriteLine("The value of y after the function call: " + y);
Console.ReadLine();
}
}
The output will be,
![Working With Ref And Out Parameter In C#]()
Now we take multiple ref parameters in our next program,
class tryref
{
public void mul(ref int i, ref int j)
{
j = i * j;
}
}
class Program
{
static void Main(string[] args)
{
tryref tf = new tryref();
int i = 5;
int j = 10;
Console.WriteLine("The value of i and j before the call :"+i+","+j);
tf.mul(ref i, ref j);
Console.WriteLine("The value of i and j after the call :" + i + "," + j);
Console.ReadLine();
}
}
The output will be,
![Working With Ref And Out Parameter In C#]()
Out parameter
Sometimes we do not want to give an initial value to the parameter; in this case we use the out parameter. The declaration of the out parameter is the same as the ref parameter. But it is used to pass the value out of a method. Now we look at the example,
class tryout
{
public int mul(int a, out int b)
{
b = a * a;
return b;
}
}
class Program
{
static void Main(string[] args)
{
tryout to = new tryout();
int x,y;
x = to.mul(10, out y);
Console.WriteLine("The output is: "+x);
Console.ReadLine();
}
}
The Output will be,
![Working With Ref And Out Parameter In C#]()
To know more about Out parameter, follow below articles