C#

FilipJ wrote:

Service-based Database

• Start by building trivial applications that perform simple math calculations (e.g. addition, multiplication, identifying unique numbers in a collection, etc.)
  
• Next, get to know how to process character strings.
  
• Along the way, introduce yourself to the different types of collections (lists, arrays, dictionaries, sets) and see how and where they're used.
  
• Then, take a step into LINQ (Language Integrate Query Language) and see how LINQ makes it easy to do the things you did manually when you started working with collections.
  
• Get to know to read and write files (text files, binary files and compressed files).
  
• Then, introduce yourself to XML serialization and learn how to store and retrieved structured data from an XML file.
  
• Next, discover simple data access from a database and introduce yourself to the basics of SQL.
  
• Dip your toes into the wonderful world of fetching data from the internet and learn how to use the HttpClient class.
  

public class MyClass
    {
    public int I;
    public int J;
    }
public struct MyStruct
    {
    public int I;
    public int J;
    }

public void UseClassAndStruct()
    {
    MyClass mc = new MyClass();
    mc.I = 1;
    mc.J = 2;
    MyStruct ms = new MyStruct();
    ms.I = 1;
    ms.J = 2;
    }

public void UseClassAndStruct()
    {
    MyClass mc = new MyClass();
    mc.I = 1;
    mc.J = 2;
    MyStruct ms;
    ms.I = 1;
    ms.J = 2;
    }

MyClass mc;

mc = new MyClass();

int i;
double j;
Point p;

int i = 3;
int j = i;
i = 4;
Console.WriteLine("{0}:{1}", i, j);

MyClass i = new MyClass();
i.I = 3;
MyClass j = i;
i.I = 4;
Console.WriteLine("{0},{1}", i.I, j.I);

MyStruct i = new MyStruct();
i.I = 3;
MyStruct j = i;
i.I = 4;
Console.WriteLine("{0},{1}", i.I, j.I);

public void ClassMod(MyClass mc)
    {
    mc.I += 100;
    Console.WriteLine(mc.I);
    }
public void StructMod(MyStruct ms)
    {
    ms.I += 100;
    Console.WriteLine(ms.I);
    }

MyClass mc = new MyClass();
mc.I = 3;
ClassMod(mc);
MyStruct ms = new MyStruct();
ms.I = 3;
StructMod(ms);
Console.WriteLine("{0},{1}", mc.I, ms.I);

103
103
103,3

List<object> mixedList = new List<object>();

mixedList.Add("Hello there");
mixedList.Add(Form1);

mixedList.Add(12);

i = i + 1;

.line 14,14 : 13,25 'int i = 777;'
IL_0001:  ldc.i4     0x309
IL_0006:  stloc.0
.line 15,15 : 13,23 'i = 1 + 1;'
IL_0007:  ldloc.0
IL_0008:  ldc.i4.1
IL_0009:  add
IL_000a:  stloc.0

OriginalGriff wrote:

That's not the way I see immutable:

public struct MyStruct
{
    public string Name;
    public int X;
    public int Y;

    public int Z { set; get; }

    public MyStruct(int z) : this() { Z = z; }
}

public void increment(ref MyStruct aStruct, int inc )
{
    aStruct.X += inc;
}

private void WriteSValues(params MyStruct[] theStructs)
{
    foreach (var theStruct in theStructs)
    {
        Console.WriteLine("Name: {0} X: {1} Y: {2} X: {3}",
            theStruct.Name,
            theStruct.X,
            theStruct.Y,
            theStruct.Z);
    }
    Console.WriteLine();
}

// test
private void TestStruct()
{
    MyStruct ms1 = new MyStruct(300) {Name = "ms1", X = 100, Y = 200};
    ms1.X += -300;

    MyStruct ms2 = ms1;
    ms2.Name = "ms2";

    WriteSValues(ms1, ms2);

    increment(ref ms1, 200);

    WriteSValues(ms1, ms2);

    ms1.X += 500;
    WriteSValues(ms1, ms2);

    MyStruct ms3 = ms2;
    ms3.Name = "ms3";
    WriteSValues(ms1, ms2, ms3);

    increment(ref ms3, 1000);
    WriteSValues(ms1, ms2, ms3);
}