public ReferenceSemantics()
{
//Entry point
// *******
// Classes
// *******
MyObj r1 = new MyObj(2, 3);
MyObj r2 = new MyObj(10, 20);
MyObj r3 = r1;
Display(r1, "r1");
Display(r2, "r2");
Display(r3, "r3");
Console.WriteLine("Update r1");
NegateObjInline(r1);
//r1.a *= -1;
//r1.b *= -1;
Display(r1, "r1");
Display(r2, "r2");
Display(r3, "r3");
// **********
// Structures
// **********
Console.WriteLine("Structures");
MyStruct s1 = new MyStruct(2, 3);
MyStruct s2 = s1;
Console.WriteLine($"s1: {s1}, s2: {s2}");
s1 = NegateStruct(s1); //Passes a copy, gets back a new value
Console.WriteLine($"s1: {s1}, s2: {s2}");
//Passing as a parameter
Console.WriteLine("Negate s2 inline");
NegateStructInline(ref s2); //Passed by reference
Console.WriteLine($"s1: {s1}, s2: {s2}");
}
public Equivalence()
{
//Entry point
// *******************
// Reference semantics
// *******************
MyObj r1 = new MyObj(2, 3);
MyObj r2 = new MyObj(-2, -3);
MyObj r3 = r1;
Display(r1, "r1");
Display(r2, "r2");
Display(r3, "r3");
Console.WriteLine("Update r1");
r1.a *= -1;
r1.b *= -1;
Display(r1, "r1");
Display(r2, "r2");
Display(r3, "r3");
//Compare two absolutely equal objects
if (r1.Equals(r3))
{
Console.WriteLine("r1 Equals r3");
}
else
{
Console.WriteLine("r1 is not Equal to r3");
}
if (r1 == r3)
{
Console.WriteLine("r1 is a reference to r3");
}
else
{
Console.WriteLine("r1 is not a reference to r3");
}
Console.WriteLine("***** Test for equality *****");
Console.WriteLine("Now set the values of r2 to the same values as r1");
//Compare two similar objects
r2.a = r1.a;
r2.b = r1.b;
Display(r1, "r1");
Display(r2, "r2");
if (r1.Equals(r2))
{
Console.WriteLine("r1 has the same values as r2");
}
else
{
Console.WriteLine("r1 has different values to r2");
}
if (r1 == r2)
{
Console.WriteLine("r1 is a reference to r2");
}
else
{
Console.WriteLine("r1 is not a reference to r2");
}
// **** Strucures ***
MyStruct s1 = new MyStruct(10, 20);
MyStruct s2 = new MyStruct(10, 20);
//if (s1 == s2) does not compile
if (s1.Equals(s2))
{
Console.WriteLine("s1 and s2 are the same!");
}
else
{
Console.WriteLine("s1 and s2 are not the same!");
}
}
void Display(MyObj obj, [CallerMemberName] string memberName = "") => Console.WriteLine(memberName + $" = {obj}");
// Parameter is a reference type, so can be modified inline
static void NegateObjInline(MyObj obj)
{
obj.a *= -1;
obj.b *= -1;
}
