static void Square1(int x)
{
     x *= x;
     Console.WriteLine(“The value inside the method: {0}”, x);
}
static void Main()
{
     int i = 5;
     Console.WriteLine(“i={0}”, i);
     Square1(i);
     Console.WriteLine(“i={0}”, i);
}

i=5
The value inside the method: 25
i=5

static void ChangeArray1(int[] arr)
{
     arr[0]=888;       // 원본 배열의 첫번째 값은 888로 변경
     arr = new int[5] {-3, -1, -2, -3, -4}; // local 변수 재지정
     Console.WriteLine(“The value inside the method: arr[0]={0}”, arr[0]);
}
static void Main()
{
     int[] myArray = {1, 4, 5};
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
     ChangeArray1(myArray);
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
}

myArray[0]=1
The value inside the method: arr[0]=-3
myArray[0]=888

static void Square2(ref int x)
{
     x *= x;
     Console.WriteLine(“The value inside the method: {0}”, x);
}
static void Main()
{
     int i = 5;
     Console.WriteLine(“i={0}”, i);
     Square2(ref i);
     Console.WriteLine(“i={0}”, i);
}

i=5
The value inside the method: 25
i=25

static void ChangeArray2(ref int[] arr)
{
     arr[0]=888;       // 원본 배열의 첫번째 값은 888로 변경
     arr = new int[5] {-3, -1, -2, -3, -4}; // 원본 배열이 다시 변경
     Console.WriteLine(“The value inside the method: arr[0]={0}”, arr[0]);
}
static void Main()
{
     int[] myArray = {1, 4, 5};
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
     ChangeArray2(ref myArray);
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
}

myArray[0]=1
The value inside the method: arr[0]=-3
myArray[0]=-3

static void Square3(int x, out int result)
{
     result = x*x;
     Console.WriteLine(“The value inside the method: {0}”, result);
}
static void Main()
{
     int i = 5;
     Console.WriteLine(“i={0}”, i);
     int result;
     Square3(i, out result);
     Console.WriteLine(“result={0}”, result);
}

i=5
The value inside the method: 25
result=25

static void ChangeArray3(out int[] arr)
{
     //arr[0]=888;       // use of unassigned out parameter ‘arr’ ERROR
     arr = new int[5] {-3, -1, -2, -3, -4}; // 원본 배열이 변경
     Console.WriteLine(“The value inside the method: arr[0]={0}”, arr[0]);
}
static void Main()
{
     int[] myArray = {1, 4, 5};
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
     ChangeArray3(out myArray);
     Console.WriteLine(“myArray[0]={0}”, myArray[0]);
}

myArray[0]=1
The value inside the method: arr[0]=-3
myArray[0]=-3