int result =-1;
if (!Int32.TryParse(SomeString, out result){
    // log bad input
}

return result;

using System;
public class MyClass
{
   public static int TestOut(out char i)
   {
      i = 'b';
      return -1;
   }

   public static void Main()
   {
      char i;   // variable need not be initialized
      Console.WriteLine(TestOut(out i));
      Console.WriteLine(i);
   }
}

using System;
class ParameterTest
{
 static void Mymethod(out int Param1)
 {
  Param1=100;
 }
 static void Main()
 {
  int Myvalue=5;
  MyMethod(Myvalue);
  Console.WriteLine(out Myvalue);
 }
}

public struct BigStruct
{
  public int A, B, C, D, E, F, G, H, J, J, K, L, M, N, O, P;
}

SomeMethod(instanceOfBigStruct); // A copy is made of this 64-byte struct.

SomeOtherMethod(out instanceOfBigStruct); // No copy is made

public void ReferenceExample(SomeReferenceType s)
 {
   s.SomeProperty = "a string"; // The change is persisted to outside of the method
 }

 public void ValueTypeExample(BigStruct b)
 {
   b.A = 5; // Has no effect on the original BigStruct that you passed into the method, because b is a copy!
 }

 public void ValueTypeExampleOut(out BigStruct b)
 {
   b = new BigStruct();
   b.A = 5; // Works, because you refer to the same thing here
 }

int a;
if(TrySomething(out a)) {}

int a;
if(TrySomething(ref a)) {}

int a = 0;
if(TrySomething(ref a)) {}

public void Example(SomeReferenceType s)
{
  s = null;
}

public void Example1(ref SomeReferenceType s)
{
  s = null; // Sets whatever you passed into the method to null
}

public bool TryGet(
   string key,
   out string value
)

string value;
if (!lookupDictionary.TryGet("some key", out value))
  value = "default";