public void AnsweringNazeesQuestionAboutAuditTrails()
{
Person mickey = new Person("Mickey Phoenix", 40);
mickey.Name = "Meowse";
// Actually doing this, behind the scenes
// mickey.set_Name("Meowse");
Console.WriteLine(mickey.Name);
// Actually doing this, behind the scene
// Console.WriteLine(mickey.get_Name());
mickey.Name = "Moose";
mickey.Name = "Michael David Phoenix";
mickey.Name = "Mickey Phoenix";
foreach (string name in mickey.NameHistory)
{
Console.WriteLine("Name was: " + name);
}
}
public void BreakingYourBrains()
{
Person mickey = new Person("Mickey Phoenix", 40); // the object formerly known as mickey
// Person alsoMickey = mickey;
// Person stillAnotherAliasForMickey = mickey;
// Person anotherWayToTalkAboutTheSameObject = alsoMickey;
Person mickeySpouse = new Person("Susan Winthrop", 41); // the object formerly known as susan
mickey.BestFriend = mickeySpouse;
mickeySpouse.BestFriend = mickey;
// What do these print?
Console.WriteLine(mickey.BestFriend.Name); // This will print out "Susan Winthrop"
Console.WriteLine(mickeySpouse.BestFriend.Name); // This will print out "Mickey Phoenix"
// Very confusing line
mickey.BestFriend.BestFriend.BestFriend.BestFriend.BestFriend.Name = "Bartholomew Cubbins";
// What do these print?
Console.WriteLine(mickey.Name); // Prints "Mickey Phoenix"
Console.WriteLine(mickeySpouse.Name); // Prints "Bartholomew Cubbins"
// Slightly less confusing equivalent to "Very confusing line" above, with
// interim variables used to give names to things in between.
Person mickeysBestFriend = mickey.BestFriend;
Person mickeyAgain = mickeysBestFriend.BestFriend;
Person stillMickeysBestFriend = mickeyAgain.BestFriend;
Person onceAgainMickey = stillMickeysBestFriend.BestFriend;
Person yepStillMickeysSpouse = onceAgainMickey.BestFriend;
yepStillMickeysSpouse.Name = "Bartholomew Cubbins, III";
// What do these print?
Console.WriteLine(mickey.Name); // Prints "Mickey Phoenix"
Console.WriteLine(mickeySpouse.Name); // Prints "Bartholomew Cubbins, III"
// Analysis question: which variables now hold references to "the object formerly known as susan"?
// mickeySpouse
// mickeysBestFriend
// stillMickeysBestFriend
// yepStillMickeysSpouse
// And which hold references to "the object formerly known as mickey"?
// mickey
// mickeyAgain
// onceAgainMickey
// All of the following lines change the Name property of the object formerly known as mickey
mickey.Name = "Hermione Granger";
mickeyAgain.Name = "Harry Potter";
onceAgainMickey.Name = "Severus Snape";
mickeyAgain.Name = "Mickey Phoenix";
mickeySpouse.BestFriend.Name = "Weasley";
yepStillMickeysSpouse.BestFriend.Name = "Luna";
mickey.BestFriend.BestFriend.Name = "Mickey Phoenix";
// This declares a named bucket, "hello", which holds a reference to a string object
// somewhere in memory.
string hello;
// This creates a "string constant" with the contents "Hello World", which lives
// somewhere in the computer's memory. It then copies the location of that
// string constant, the address of that string constant, into the location named "hello"
hello = "Hello World";
// This looks up the string constant whose address is contained in the bucket named
// "hello", and prints it out on the console.
Console.WriteLine(hello);
// This makes a new string by combining "Goodbye Cruel World" and ", I'm leaving you today",
// and stores it in some location in memory.
hello = "Goodbye Cruel World" + ", I'm leaving you today";
Console.WriteLine(hello);
// This replaces that reference with a reference to a new string constant.
// The garbage collector can now garbage collect the string that was constructed by the addition above
hello = "Goodbye";
Console.WriteLine(hello);
}
public void TwoDifferentObjectsWithSharedReference()
{
Person mickey = new Person("Mickey Phoenix", 40); // "the object formerly known as 'mickey'
Person susan = new Person("Susan Winthrop", 41); // "the object formerly known as 'susan'"
Person joe = new Person("Joe Schmoe", 39); // "the object formerly known as 'joeschmoe'"
mickey.BestFriend = joe; // mickey.BestFriend is now a reference to the object formerly known as joeschmoe
susan.BestFriend = joe; // susan.BestFriend is now a reference to the object formerly known as joeschmoe
// Which means that any changes to the object formerly known as joeschmoe
// will change both the attributes of Mickey's best friend and the
// attributes of Susan's best friend
joe.Name = "John Doe";
// What will these print out?
Console.WriteLine(mickey.BestFriend.Name);
Console.WriteLine(susan.BestFriend.Name);
mickey.BestFriend.Name = "Joseph Schmoeseph";
// What will this print?
Console.WriteLine(joe.Name);
Console.WriteLine(mickey.BestFriend.Name);
Console.WriteLine(susan.BestFriend.Name);
}
public void TwoDifferentObjectsExample()
{
Person mickey = new Person("Mickey Phoenix", 40);
Person susan = new Person("Susan Winthrop", 41);
mickey.Address = "1724 17th Ave., Seattle, WA 98122";
// This copies a value from the "mickey" object to the "eva" object -- specifically, the value that is "the location
// of the address string".
susan.Address = mickey.Address;
// All this does is change the Address property of the "mickey object" -- not the Address property of the "eva object"
mickey.Address = "301 1st St., Tukwila, WA 98188";
Console.WriteLine(susan.Address); // what will this print?
}
public void SharedReferenceExample()
{
Person mickey = new Person("Mickey Phoenix", 40);
// Does not copy values from the "mickey" object to the "instructor" object
// Just copies the reference to the object (the pointer to the memory location of the object) from "mickey" to "instructor"
Person instructor = mickey;
Console.WriteLine(mickey.Name);
Console.WriteLine(instructor.Name);
instructor.Name = "Michael Phoenix";
Console.WriteLine(mickey.Name); // prints out "Michael Phoenix"
mickey.Age = 41;
Console.WriteLine(instructor.Age); // prints out "41"
}
