Public keyword C# Example

C# > Keywords > public

Public is the most permissive access level. 

It is no restrictions on accessing public members.






Example

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace WindowsFormsApplication12

{

    public partial class Form1 : Form

    {

        public class Person

        {

            public string Name;

            public int Age;

        }

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            Person p = new Person();

            p.Name = "John";

            p.Age = 35;

        }

    }

}

C# > Types > Enum > String Enum

Implement Strings Enum in C#

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Reflection;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace EnumString

{

    public partial class Form1 : Form

    {

        public enum Cars

        {

            [Description("Audi")] Audi,   

            [Description("Bmw")] Bmw,   

            [Description("Land Rover")] LandRover

        }

        public static string GetCarDescription(Enum car)

        {

            FieldInfo fi = car.GetType().GetField(car.ToString());

            DescriptionAttribute[] da = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);

            if (da != null && da.Length > 0)       

                return da[0].Description;

            else      

                return da.ToString();

        }

        public static IEnumerable EnumToList()

        {   

            Type type = typeof(T);   

            Array vals = Enum.GetValues(type);   

            List valList = new List(vals.Length);   

            foreach (int val in vals)   

            {

                valList.Add((T)Enum.Parse(type, val.ToString()));   

            }

            return valList;

        }

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            foreach (Cars car in EnumToList<Cars>())

            {

                comboBox1.Items.Add(GetCarDescription(car));

            }

        }

    }

}

Format SQL Server Example

SQL Server > Built-in Functions > FORMAT

Formats a values to specific format.






Example:

A.

DECLARE @d DATETIME = '10/17/2014';

SELECT FORMAT ( @d, 'd', 'en-US' ) AS 'US English Result'

      ,FORMAT ( @d, 'd', 'de-de' ) AS 'German Result'

      ,FORMAT ( @d, 'd', 'ro-ro' ) AS 'Romanian Result';

Result

US English Result German Result Romanian Result

10/17/2014         17.10.2014 17.10.2014

B.

DECLARE @d DATETIME = GETDATE();

SELECT FORMAT( @d, 'dd/MM/yyyy')

Result

(No column name)

13/06/2014

C.

SELECT FORMAT(100, 'N', 'en-us') AS 'Number Format',FORMAT(200, 'C', 'en-us') AS 'Currency Format'

Result

Number Format Currency Format

100.00         $200.00

Lower SQL Server Example

SQL Server > Built-in Functions > LOWER

Converts uppercase character data to lowercase.

Example

SELECT lower('SQL SERVER')

Result:

sql server

Dictionary C# Example

C# > Generics > Dictionary 

Dictionary is a collection of keys and values.
Retrieving a value by using its key is very fast because the Dictionary class is implemented as a hash table.

Example

    Dictionary<string, string> accesCode = new Dictionary<string, string>();

            accesCode.Add("AAA", "PERSON 1");

            accesCode.Add("BBB", "PERSON 2");

            accesCode.Add("CCC", "PERSON 3");

            string code = "";

            accesCode.TryGetValue("xxx", out code); // code = null

            accesCode.TryGetValue("CCC", out code); // code = PERSON 3

            if (!accesCode.ContainsKey("DDD"))

                accesCode.Add("DDD", "PERSON 4");

            foreach (KeyValuePair<string, string> kvp in accesCode)

            {

                MessageBox.Show(kvp.Key + kvp.Value);

            }

Join two tables Linq example C#

C# > LINQ > Join

Join is association of objects that share a common attribute.


Example:

DataTable dtOrder = new DataTable("order");

dtOrder.Columns.Add("id", Type.GetType("System.Int32"));

dtOrder.Columns.Add("customer", Type.GetType("System.String"));

DataRow dr = dtOrder.NewRow();

dr["id"] = 1;

dr["customer"] = "X Company";

dtOrder.Rows.Add(dr);

dr = dtOrder.NewRow();

dr["id"] = 2;

dr["customer"] = "Y Company";

dtOrder.Rows.Add(dr);

DataTable dtProduct = new DataTable("product");

dtProduct.Columns.Add("order_id", Type.GetType("System.Int32"));

dtProduct.Columns.Add("product", Type.GetType("System.String"));

dr = dtProduct.NewRow();

dr["order_id"] = 1;

dr["product"] = "Product 1";

dtProduct.Rows.Add(dr);

dr = dtProduct.NewRow();

dr["order_id"] = 1;

dr["product"] = "Product 2";

dtProduct.Rows.Add(dr);

var orderProducts = from order in dtOrder.AsEnumerable()

                    join product in dtProduct.AsEnumerable() on order.Field<int>("id")                               equals product.Field<int>("order_id")

                     select new

                                {

                                    OrderId = order.Field<int>("id"),

                                    Product = product.Field<string>("product")

                                };

StringBuilder C# Example

C# > Text > StringBuilder 

StringBuilder is used when

• you want to create or modify a string without creating a new object
• increase performance when concatenating many strings together in a loop.

Example:

StringBuilder str = new StringBuilder("Product 1");

str.AppendLine(); // new line

str.Append("Product 2");

str.AppendLine();

str.AppendFormat("Total {0:C} ", 40);

textBox1.Text = str.ToString();