dev/CSHARP/Lessons.md

###Классы и объекты

```
Person tom = new Person();
string personName = tom.name;
int personAge = tom.age;
Console.WriteLine($"name: {personName} age: {personAge}");

tom.name = "Tom";
tom.age = 37;
tom.Print();

class Person
{
    public string name = "Undefined";
    public int age;

    public void Print()
    {
        Console.WriteLine($"Имя: {name} Возраст: {age}");
    }
}
```

###Конструкторы, инициализаторы и деконструкторы

```
Person tom = new Person();
Person bob = new Person("Bob");
Person sam = new Person("Sam", 25);
tom.Print();
bob.Print();
sam.Print();

class Person
{
    public string name;
    public int age;
    public Person()
    {
        name = "Unknown";
        age = 18;
    }
    public Person(string n) { name = n; age = 18; }
    public Person(string n, int a) { name = n;  age = a; }

    public void Print()
    {
        Console.WriteLine($"name: {name} age: {age}");
    }

}
```
```
Person sam = new Person("Sam", 25);
sam.Print();

class Person
{
    public string name;
    public int age;
    public Person()
    {
        name = "Unknown";
        age = 18;
    }
    public Person(string name) { this.name = name; age = 18; }
    public Person(string name, int age)
    {
        this.name = name;
        this.age = age;
    }
    public void Print()
    {
        Console.WriteLine($"name: {name} age: {age}");
    }
}
```

###Цепочка вызова конструкторов

```
Person sam = new Person("Sam", 25);
sam.Print();

class Person
{
    public string name;
    public int age;
    public Person() : this("Unknown") { }
    public Person(string name) : this(name, 18) { }
    public Person(string name, int age)
    {
        this.name = name;
        this.age = age;
    }
    public void Print() => Console.WriteLine($"Name: {name} Age: {age}");
}
```

###Первичные конструкторы

```
var tom = new Person("Tom", 38);
Console.WriteLine(tom);

public class Person(string name, int age)
{
    public Person(string name) : this(name, 18) { }
    public void Print() => Console.WriteLine($"name: {name}, age: {age}");
}
```

###Инициализаторы объектов

```
Person tom = new Person { name = "Tom", company = { title = "Microsoft" } };
tom.Print();

class Person
{
    public string name;
    public Company company;
    public Person()
    {
        name = "Undefinde";
        company = new Company();
    }
    public void Print() => Console.WriteLine($"name: {name} company: {company.title}");
}

class Company
{
    public string title = "Unknown";
}
```

###Деконструкторы

```
Person person = new Person("Tom", 33);
(string name, int age) = person; //(_, int age) = person если нужен только возраст
Console.WriteLine(name);


class Person
{
    string name;
    int age;
    public Person(string name, int age)
    {
        this.name;
        this.age;
    }
    public void Deconstruct(out string personName, out int personAge)
    {
        personName = name;
        personAge = age;
    }
}
```

###Класс Program и метод Main. Программы верхнего уровня

```
string hello = "Hello";
Print(hello);

void Print(string message)
{
    Console.WriteLine(message);
}

Person tom = new();
tom.SayHello();

class Person
{
    public void SayHello() => Console.WriteLine("Hello");
}
```

###Структуры

```
struct Person
{
    public string name;
    public int age;

    public void Print()
    {
        Console.WriteLine($"Name: {name} Age: {age}");
    }
}
```

###Типы значений и ссылочные типы
###Область видимости переменных (контекст)