c 1 introduction to programming and the c language

c 1 introduction to programming and the c language


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point). 
Then test whether the player has won, or whether the house has won. If the player has won, the method 
returns true, and if the house has won the method returns false. If the game is not decided after the first 
roll, roll again and repeat until the game is decided.
Note also that the methods Cast() and Show() are direct copies of the corresponding methods from the 
previous program.
Comment
The above version of the game is somewhat simplified, and there are more rules associated with the 
game. If you play the game, as described above, the player and the house is almost the same probability 
of winning with a slight predominance for the house \u2013 and it should also like to be if the house should 
not go bankrupt.
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C# 1 Introduction to programming and the C# language 
70 
Part 2 Object Oriented Programming
Part 2 Object Oriented 
Programming
Applications must process data, and data must be represented and stored, and that is what variables are 
used for. A language like C# has a number of built-in types for variables, but often would you need to 
define your own data types that better reflect the job that the program must solve. That is where the 
class concept comes into play. A class is something that defines a concept or thing within the program\u2019s 
area of concern, and there can be said a lot about what are classes and what not, but basically is a class a 
type. It\u2019s a bit more than just a simple type as a class partly defines how data should be represented, but 
also what you can do with the data of that type. A class defines both how the type should be represented 
and what operations you can perform on the variables of that type.
When you create variables whose type is a class, we talk about objects, so that a variable of a class type 
is called an object, but really there is no much difference between a variable and an object, and there 
is a good piece of the road no reason to distinguish between the two. But dig a little deeper, there is a 
reason that has to do with how the variables and objects are allocated in the machine\u2019s memory.
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C# 1 Introduction to programming and the C# language 
71 
Part 2 Object Oriented Programming
Variables of types such as int, double, bool, char, etc. are called variables of simple types. For a running program 
is allocated a stack, that is a memory area used by the application to store variables. The stack is very effective 
so it is very effective to the program continuously setting up and removal of variables if necessary. This is 
known as a stack, because one can think of a stack as a data structure illustrated in the following manner:
When the program creates a new variable, it happens at the top of the stack \u2013 where the arrow points, 
and when a variable is removed, it is the one that lies at the top of the stack. All of the simple data types 
have the property that a variable always have the same size. For example fills an int the same regardless 
of what value it has. Therefore, such variables are stored directly on the stack, because the compiler 
knows how much they fill. If, for example you write as follows
int a = 23;
then there will on the stack be created a variable of the type int with the space that an int requires and 
the value 23 are stored there. Variables that are stored directly on the stack in this way are called value 
types, and all the built-in types \u2013 except string \u2013 are value types.
Things are different with variables of reference types such as variables that have a class type. They must 
be explicitly created with new. If, for example you have a class named Coin (see below) and you want to 
create such an object, you must write
Coin c = new Coin();
It looks like, how to create a simple variable. The variable is named c. When new are performed what 
happens is that on the so-called heap there are created an object on the basis of the type Coin. One can 
think of the heap as a memory pool from which the machine can allocate memory as needed. On the 
stack is created as usual, a variable with the type of Coin, but what it is saved on the stack, is not the 
value of the Coin object, but instead a reference to the object on the heap. All references have the same 
size regardless of the type and can therefore be stored on the stack. That\u2019s why we call it a reference 
type. How exactly one object is created on the heap is determined by a so-called heap manager, there is 
a program that constantly runs and manages the heap. It is also the heap manager, which automatically 
removes an object when there is no longer needed.
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C# 1 Introduction to programming and the C# language 
72 
Part 2 Object Oriented Programming
For the foregoing reasons, it is clear that the variables of value types are more efficient than objects of 
reference types. It does not mean that objects of reference types are ineffective, and in most cases it is not 
a difference which one needs to take care of, but conversely, there are also situations where the difference 
matters. It is thus important to know that there is a big difference in how value types and reference types 
are handled by the system and that in some contexts it have a major impact on how the program will 
behave, but there\u2019ll be many examples which clarify the difference. So far it is enough to know that the 
data elements can be grouped into two categories depending on their data type, so that data of value 
types are allocated on the stack and usually called variables, while data of the reference types are allocated 
on the heap and are called objects \u2013 even if there is not complete consistency between the two names.
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