Microsoft .NET Interview Questions and Answers

Question: What is a reference parameter?

Answer: Reference parameters reference the original object whereas value parameters make a
local copy and do not affect the original. Some example code is shown:
using System;
namespace Console1
{
class Class1
{
static void Main(string[] args)
{
TestRef tr1 = new TestRef();
TestRef tr2 = new TestRef();
tr1.TestValue = "Original value";
tr2.TestValue = "Original value";
int tv1 = 1;
int tv2 = 1;
TestRefVal(ref tv1, tv2, ref tr1, tr2);
Console.WriteLine(tv1);
Console.WriteLine(tv2);
Console.WriteLine(tr1.TestValue);
Console.WriteLine(tr2.TestValue);
Console.ReadLine();
}
static public void TestRefVal(ref int tv1Parm,
int tv2Parm,
ref TestRef tr1Parm,
TestRef tr2Parm)
{
tv1Parm = 2;
tv2Parm = 2;
tr1Parm.TestValue = "New value";
tr2Parm.TestValue = "New value";
}
}
}
class TestRef
{
public string TestValue;
}
The output for this is:
2
1
New value
New value