Visual C++ .NET/Function/Function parameter

param array parameter

<source lang="csharp">

1. include "stdafx.h"

using namespace System; int Total( int a, ... array<int>^ varargs) {

  int tot = a;
  for each ( int i in varargs)
  {
     tot += i;
  }
  return tot;

} int main() {

  int sum1 = Total(100, 200, 350);
  Console::WriteLine("First total: {0}", sum1);
  int sum2 = Total(1, 2, 3, 4, 5, 6, 7, 8);
  Console::WriteLine("Second total: {0}", sum2);

}

 </source>

parameter passing

<source lang="csharp">

1. include "stdafx.h"

void byvalue(int i) {

  i += 1;

} void byref(int& i) {

  i += 1;

} int main() {

  int j = 10;
  System::Console::WriteLine("Original value: " + j);
  byvalue(j);
  System::Console::WriteLine("After byvalue: " + j);
  byref(j);
  System::Console::WriteLine("After byref: " + j);

}

 </source>

pass by reference

<source lang="csharp">

1. include "stdafx.h"

using namespace System; value class Pair {

 public:
    int x;
    int y;

}; void swap_values(Pair% pair) {

   int temp = pair.x;
   pair.x = pair.y;
   pair.y = temp;

} int main() {

  Pair p;
  p.x = 5;
  p.y = 3;
  Console::WriteLine("{0} {1}", p.x, p.y);
  swap_values(p);
  Console::WriteLine("{0} {1}", p.x, p.y);

}

 </source>

pass by value

<source lang="csharp">

1. include "stdafx.h"

using namespace System; ref struct R {

  R()
  {
     val = 1;
  }
  // copy constructor
  R( R% r)
  {
     val = r.val;
  }
  property int val;

}; void f(R r_local) {

  r_local.val = 2;
  Console::WriteLine("Within f: " + r_local.val);

} int main() {

   R r;
   f(r);
   Console::WriteLine("Outside f: " + r.val);
   R^ rhat = gcnew R();
   f(*rhat);  
   Console::WriteLine("Outside f: " + rhat->val);

}

 </source>

Passing array as parameter

<source lang="csharp">

1. include "stdafx.h"

using namespace System; void set_to_one(int i, array<int>^ array_arg) {

  array_arg[i] = 1;

} int main() {

   array<int>^ array1 = { 0, 1 };
   set_to_one(0, array1);
   Console::WriteLine(" {0} {1}", array1[0], array1[1]);

}

 </source>

Passing value struct to function

<source lang="csharp">

1. include "stdafx.h"

using namespace System; value struct V {

  int a;
  int b;

}; void f(V% v) {

  v.a = 10;
  v.b = 20;

} int main() {

  V v;
  v.a = 1;
  v.b = 2;
  f(v);
  Console::WriteLine("{0} {1}", v.a, v.b);

}

 </source>