public static void modifyObject2(sampleClass obj)
{
obj.field1 = 9;
obj.field2 = 4.0;
obj.field3 = "DESERT ISLAND";
obj.field4 = false;
obj.field5 = 'Q';
}
//simply converts everything to emogee robot info
public static void modifyObject(ref sampleClass obj)
{
obj.field1 = 129302;
obj.field2 = 129302.0;
obj.field3 = "HUMAN | 😏🤖 | ROBOT"; //this works, as string decodes Unicode
obj.field4 = false;
//won't work, sadly, needs more maths before we can get the unicode character as a char.
//obj.field5 = 🤖;
obj.field5 = 'R';
}
static void Main(string[] args)
{
Console.WriteLine("Testing shared references between two lists.");
//create an empty list
List <sampleClass> list1 = new List <sampleClass>();
//create some class instances
sampleClass object1 = new sampleClass(42, 256.00, "DARKSTAR", true, 'X');
sampleClass object2 = new sampleClass(512, 15.00, "NEUTRONSTAR", false, 'N');
sampleClass object3 = new sampleClass(92169, 4509.00, "VERDANTSTAR", true, 'L');
//try as a quick add...
list1.Add(object1);
list1.Add(object2);
list1.Add(object3);
//confirm output
Console.Out.WriteLine(list1[0].GetPrintable());
Console.Out.WriteLine(list1[1].GetPrintable());
Console.Out.WriteLine(list1[2].GetPrintable());
doHR();
//works, so ... lets see if we can edit from outside the list.
object1.field3 = "BLACK HOLE";
//both refer to the same object????
Console.Out.WriteLine(list1[0].GetPrintable());
doHR();
//Oh yes, yes, they do....
//so lets see if 2 lists will share.
//create another empty list of the same type.
//quickly add the 3 objects to the second list.
List <sampleClass> list2 = new List <sampleClass>()
{
object3, object2, object1
};
//confirm the order...
Console.Out.WriteLine(list2[0].GetPrintable());
Console.Out.WriteLine(list2[1].GetPrintable());
Console.Out.WriteLine(list2[2].GetPrintable());
doHR();
//Now to modify each and every object, we won't use ref here, but will do it manually.
object1.field1 = 234;
object1.field2 = 324.056;
object1.field3 = "SINGULARITY";
object1.field4 = true;
object1.field5 = '•';
//confirm changes to object, which should be reflected in both lists....
//object1
Console.Out.WriteLine(object1.GetPrintable());
doHR();
//confirm reference to object1
Console.Out.WriteLine(list1[0].GetPrintable());
doHR();
//conform yet another reference to object1, also...
Console.Out.WriteLine(list2[2].GetPrintable());
doHR();
//in conclusion, objects put into a list are PASSED BY REFERENCE.
// :)
//now lets use a method to modify the referenced-object.... in a list.
//note how we are using a reference
modifyObject(ref object1);
//confirm all changes...
Console.Out.WriteLine(list1[0].GetPrintable());
doHR();
//conform yet another reference to object1, also...
Console.Out.WriteLine(list2[2].GetPrintable());
doHR();
//see if we even need to bother with ref
//new object
sampleClass object4 = new sampleClass(35, (double)Math.PI, "🏝️", false, 'D');
Console.Out.WriteLine(object4.GetPrintable());
doHR();
//add it to the lists with the no-ref method
addToBothLists(list1, list2, object4);
//confirm all changes...
Console.Out.WriteLine(list1[0].GetPrintable());
Console.Out.WriteLine(list1[1].GetPrintable());
Console.Out.WriteLine(list1[2].GetPrintable());
Console.Out.WriteLine(list1[3].GetPrintable());
doHR();
Console.Out.WriteLine(list2[0].GetPrintable());
Console.Out.WriteLine(list2[1].GetPrintable());
Console.Out.WriteLine(list2[2].GetPrintable());
Console.Out.WriteLine(list2[3].GetPrintable());
doHR();
//see if they are unique objects, or also references.
modifyObject2(object4);
Console.Out.WriteLine(object4.GetPrintable());
doHR();
//confirm all changes...
Console.Out.WriteLine(list1[0].GetPrintable());
Console.Out.WriteLine(list1[1].GetPrintable());
Console.Out.WriteLine(list1[2].GetPrintable());
Console.Out.WriteLine(list1[3].GetPrintable());
doHR();
Console.Out.WriteLine(list2[0].GetPrintable());
Console.Out.WriteLine(list2[1].GetPrintable());
Console.Out.WriteLine(list2[2].GetPrintable());
Console.Out.WriteLine(list2[3].GetPrintable());
doHR();
//which works
// indicates that ref is not needed at all.... for reference varables
// and that no matter what, lists take references to objects and are
// shallow copy.
//
// For reference-type variables,
// if a pass-by-value is desired,
// a deep-copy method will be required.
// 1. create the new object of the same class
// 2. copy all the variables from one object to another
// 3. put new object into list.
}
public static void addToBothLists(List <sampleClass> listun, List <sampleClass> listdeux, sampleClass obj)
{
listun.Add(obj);
listdeux.Add(obj);
}