using System; using System.Collections.Generic; using System.Text; class Point { public Point() { this.x = -1; this.y = -1; objectCount++; } public Point(int x, int y) { this.x = x; this.y = y; objectCount++; } public double DistanceTo(Point other) { int xDiff = this.x - other.x; int yDiff = this.y - other.y; return Math.Sqrt((xDiff * xDiff) + (yDiff * yDiff)); } public static int ObjectCount() { return objectCount; } private int x, y; private static int objectCount = 0; } class Program { static void Main(string[] args) { try { Point origin = new Point(); Point bottomRight = new Point(1024, 1280); double distance = origin.DistanceTo(bottomRight); Console.WriteLine("Distance is {0}", distance); Console.WriteLine("No of Point objects: {0}", Point.ObjectCount()); } catch (Exception ex) { Console.WriteLine(ex.Message); } } }
ASP.NET & Csharp (C#)
ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .
Object assignment
using System; public class Foo { public int i; } class RefTest1App { static void Main(string[] args) { Foo test1 = new Foo(); test1.i = 1; Foo test2 = new Foo(); test2.i = 2; Console.WriteLine("BEFORE OBJECT ASSIGNMENT"); Console.WriteLine("test1.i={0}", test1.i); Console.WriteLine("test2.i={0}", test2.i); Console.WriteLine(); test1 = test2; Console.WriteLine("AFTER OBJECT ASSIGNMENT"); Console.WriteLine("test1.i={0}", test1.i); Console.WriteLine("test2.i={0}", test2.i); Console.WriteLine(); test1.i = 42; Console.WriteLine("AFTER CHANGE TO ONLY TEST1 MEMBER"); Console.WriteLine("test1.i={0}", test1.i); Console.WriteLine("test2.i={0}", test2.i); } }
Catch NullReferenceException Exception
using System; class MyClass { public int Value; } class MainClass { public static void Main() { try { MyClass MyObject = new MyClass(); MyObject = null; MyObject.Value = 123; } catch (NullReferenceException) { Console.WriteLine("Cannot reference a null object."); } } }
Calling a Class Method on a Class
using System; public class MainClass { public static void Main() { string firstName = "J"; string lastName = "R"; string name = string.Format("{0} {1}", firstName, lastName); Console.WriteLine(name); } }
Calling an Instance Method on an Object
using System; public class MainClass { public static void Main() { string name = "Joe"; Console.WriteLine(name.ToUpper()); } }
Object.ReferenceEquals Method
using System; public class Starter { public static void Main() { Employee obj1 = new Employee(5678); Employee obj2 = (Employee)obj1.Clone(); if (Employee.ReferenceEquals(obj1, obj2)) { Console.WriteLine("objects identical"); } else { Console.WriteLine("objects not identical"); } } } class Employee : ICloneable { public Employee(int id) { if ((id < 1000) || (id > 9999)) { throw new Exception( "Invalid Employee ID"); } } public object Clone() { return MemberwiseClone(); } }
Object Copy and Clone
using System; public class Name { public string firstName; public string lastName; public Name(string firstName, string lastName) { this.firstName = firstName; this.lastName = lastName; } public void Display() { Console.WriteLine("firstName = " + firstName); Console.WriteLine("lastName = " + lastName); } public static Name Copy(Name car) { return (Name) car.MemberwiseClone(); } } class Test { public static void Main() { Name myName = new Name("T", "M"); Name myOtherName = new Name("P", "B"); Console.WriteLine("myName details:"); myName.Display(); Console.WriteLine("myOtherName details:"); myOtherName.Display(); // perform a memberwise clone of myName using the Name.Copy() method Console.WriteLine("Performing a memberwise clone of myName to myOldName"); Name myOldName = Name.Copy(myName); Console.WriteLine("myOldName details:"); myOldName.Display(); } }