A class is a data structure containing data and associated behavior. You use the class keyword in C# to define a new class. You use your user-defined class in the same way that you use built-in classes in the .NET Framework.
You can create an instance of a class, also known as an object, using the new keyword. Each instance of a class has its own copy of the data defined by the class.
Here’s an example, a declaration of a new Person class.
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| public class Person{ public string FirstName; public string LastName; public int Age; public string DescribeMe() { return string.Format("{0} {1} is {2} yrs old.", FirstName, LastName, Age); }} |
Once the class is defined, we can create new instances of the class, read/write its data and call its methods.
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| Person p = new Person();p.FirstName = "James";p.LastName = "Joyce";p.Age = 40;string desc = p.DescribeMe(); |