// END INTERLUDE...
public static void Objects()
{
//4. The foundations of imperative programming (OO)
/*
* We need to go back to state, behaviour, identity and type
* and clarify what each now mean as applied to *objects*
* (...which are not merely simple values).
*
*/
//sherlock is the object, Detective its type
Detective sherlock = new Detective
{ //NB. we can set the state of the object when we create it
name = "Sherlock Holmes",
height = 1.81,
weight = 70
};
//what is its state?
System.Console.WriteLine(sherlock.name);
System.Console.WriteLine(sherlock.height);
System.Console.WriteLine(sherlock.weight);
//how does it's state change?
sherlock.Eat(0.5); //sherlock increases its own weight
//what is its behaviour?
// its methods, eg. sherlock.Eat
//identity?
var me = sherlock;
var you = sherlock;
System.Console.WriteLine(me == you);
System.Console.WriteLine(sherlock == new Detective
{
name = "Sherlock Holmes"
});
// sherlock == someone else called sherlock ? NOPE
/*
* for simple data values identity and equality are the same
* for objects these come apart
*
* conditions underwhich we might want to say two objects are "equal"
* (eg. equal in price) do not imply the objects are the same
*
* your house might be "equal-to" a £300,000 check
* but I cannot demolish your house and replace it with a piece of paper
*
* identity means (according to Leibniz at least) equal in every possible way
*
* For x to identitical to y is for x to be y
* For Michael to be identiical to Mike is for Michael and Mike to refer to exactly the same object.
*/
}