C# Tutotial : Comments , Loops , Methods / functions : Part 6

Comments in c#

Sing line comment

• e.g. //Your comment

Multiline comment

• e.g.  /* Your comment */

XML documentation, to give description for class

• Just type /// above class or method, it will automatically open description tag
• e.g.

/// <summary>

/// Your description

/// </summary>

/// <param name="args"></param>

Loops in C#

• While loop
• do loop
• for loop
• foreach loop
• do while loop

Do While loop

do some thing while checking some thing.

e.g.

            var a = 5;

            var b = 10;

            do

            {

                a++;

            }

            while (a == b);

In above e.g. do will be executed 5 times until a == b i.e. a = 10 and b = 10.

Method / Functions in c#

[attributes]

access-modifiers returnType methodName(parameters)

{

method body

}

1. static method is invoked by using class name.
2. instance method is invoked by creating object of class.

Method parameters types

• Value parameter

             static void SquareIt(int x)

            // The parameter x is passed by value.

            // Changes to x will not affect the original value of x.

            {

                x *= x;

                System.Console.WriteLine("The value inside the method: {0}", x);

            }

            static void Main()

            {

                int n = 5;

                System.Console.WriteLine("The value before calling the method: {0}", n);

                SquareIt(n);  // Passing the variable by value.

                System.Console.WriteLine("The value after calling the method: {0}", n);

            }

In above e.g. n is passed to the function SquareIt, in which change in value of x 

will not affect n

• Reference parameter

             static void SquareIt(ref int x)

            // The parameter x is passed by value.

            // Changes to x will not affect the original value of x.

            {

                x *= x;

                System.Console.WriteLine("The value inside the method: {0}", x);

            }

            static void Main()

            {

                int n = 5;

                System.Console.WriteLine("The value before calling the method: {0}", n);

                SquareIt(ref n);  // Passing the variable by value.

                System.Console.WriteLine("The value after calling the method: {0}", n);

            }

In above e.g. n is passed to the function SquareIt, in which change in value of x 

will affect n, where value of  n == value of x

• out parameter

        static void Main(string[] args)

        {

            var a = 0;

            GetVal(out a);

            var b = a;

        }

        static void GetVal(out int n)

        {

            var Sum = 5;

            n = Sum;

        }

In above e.g. value of a will be the value assigned in GetVal function

• parameter arrays

         static void Main(string[] args)

        {

            string[] MyStr = { "A", "B", "C" };

            PrintArr(MyStr);

        }

        static void PrintArr(string[] arr)

        {

            Console.WriteLine(arr[2].ToString());

        }

In above e.g. array string is passed to a function.

Static and Instance method

public class Circle
{
int radius;
int diameter;
}

When ever a class is initiated by instance it consumes memory every time

public class Circle
{
static int radius;
static int diameter;
}

If the method or property is static than it always consumes the same memory.