Category: C# Basics

Training day

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We learned about User-Defined-Exceptions in .NET and practiced exceptions of this type. we explored the dilemma of who should handle the exception? in our restaurant project.  next topic was testing framework. what is Test framework? why do we need it? what is Test Driven Development (TDD)? . after the discussion, we created our first Unit-Test project of a calculator, and expanded it to test our UniqueListClass

More topics covered:

• • Custom Exception ctors (+ auto generated)
  • Exception serialization requirement
  • Event viewer – how to find .NET exceptions?
  • Test importance to maintenance
  • TDD importance to development – time saver
  • Test attributes: [TestClass] [TestMethod]
  • Test exception: [ExpectedException( typeof(…) )]
  • Assert command

Links:

• • • Protected unique list (HW)
    • Class code: CustomExceptions – restaurant example
    • Class code: Adding custom exceptions to Protected unique list
    • Class code: Calculator test demo
    • Class code: Adding Test to Protected unique list
    • Lesson Summary Video
    • Homework!
    • User defined exceptions – MSDN
    • C# unit test – C-Sharp corner
    • What is TDD?

We learned about Exceptions in .NET and the SystemException vs ApplicationException. we practiced the try-catch-finally block. we learned how to stop the program in debugger using the Exceptions-Settings. we learned the benefit of the StackTrace. and finally we used throw to initiate exceptions our selves

More topics covered:

• • message field usage in self thrown exceptions
  • DivideByZeroException
  • Exceptions in arrays – IndexOutOfRangeException
  • Creating Exception object – new ExceptionClassName
  • Inner exception

Links:

• • • RoundTable solution (HW)
    • Class code: Exceptions
    • Lesson Summary Video
    • Homework!
    • Exception tree- tutorials teacher
    • Exceptions – MSDN link
    • Exception types – MSDN link

We learned about Indexers and the different types of usages. we explored creation of Generic classes using T and implementing indexer, ctor, methods, properties, ToString using type T. we saw how to make foreach available for our class using IEnumerable<T>

More topics covered:

• • Indexer methods – returning different types
  • T constrains – interface implementations, default ctor()
  • Making types out of Class<T>
  • IEnumerbale – implementation using List.GetEnumerator()

Links:

• • • MyLibrary solution (HW)
    • Class code: Indexer Garage
    • Class code: Generics class <T>
    • Class code: Generic + foreach exercise solution
    • Lesson Summary Video
    • Homework!
    • Indexer – MSDN link
    • Generics classes – MSDN link
    • IEnumerable<T> – MSDN link
    • Generic constrains – MSDN

   

We learned about Dictionary and Hashmaps and the hash algorithm usage to store and retrieve data. we used int, string and object types for both keys and values and explored the Dictionary API

More topics covered:

• • Hash collision
  • Object Hash code as key
  • Dictionary.TryGetValue
  • Dictionary[ key ]
  • Dictionary.Add
  • Dictionary.ContainsKey
  • foreach (KeyValuePair<type, type> item in dictionaryName) …
  • Disadvantage of using object as a key

Links:

• • • Queue exercise solution (HW)
    • Class code: Dictionary introduction
    • Dictionary of string numbers – exercise solution
    • Lesson Summary Video
    • Hmoework!
    • Dicationary – MSDN link

   

We learned about ArrayList and the process of boxing-unboxing. we explored memory type Stack vs Heap and how .NET calls the functions using stack-frame. We saw Generic List<T> class which avoids the boxing-unboxing operations. We got familiar with the LINQ API. finally we implemented a Stack data-type functions using List commands (behind the scenes)

More topics covered:

• • Garbage Collector (GC) – memory cleaning
  • Recursion methods – StackOverflow issues
  • Stack frame local variables
  • Typesafe
  • List<T>.Insert
  • List<T>.Count
  • List<T>.RemoveAt
  • List<T>.Clear
  • List implementation uses an Array

Links:

• • • Operation overloading solution (HW)
    • Class code: ArrayList List<T> code
    • MyStack – exercise solution
    • Lesson Summary Video
    • Homework!
    • Stack vs Heap – c-sharpcorner

   

We learned about operator overloading. we used dotPeek to investigate c# “under the hood” code. we saw operator == requires also != and also Equals

More topics covered:

• • Object class methods
  • operatos overloading: >= <= * /
  • mscorlib.dll
  • Object.RefernceEquals

Links:

• • • Serialization code solution (HW)
    • Class code: Point operator overloading
    • Lesson Summary Video
    • Homework!
    • Operator Overloading – MSDN link
    • dotPeek download – free

   

We learned about the serialization and deserialization process. we used the XML format. we wrote to a file using file-stream and XmlSerializer

More topics covered:

• • Stream
  • FileStream class
  • serialization of an array
  • access modifiers required for serialization
  • XML attributes for customizing the serialization
  • c# using() { … }
  • add link to a project

Links:

• • • Comparable code solution (HW)
    • Class code: person XML serializer
    • Lesson Summary Video
    • Homework!
    • Serialization – MSDN link
    • C# XmlSerializer – MSDN link
    • XML – fun link
    • FileStream – MSDN link

   

We learned about array sorting using IComparable and IComparer. we implemented the Generics form of the interfaces IComparable IComparer. we also performed casting using (type)obj.

More topics covered:

• • default value of an object inside a class is null
  • as + null check is better than is + casting
  • IComparer class could be in the same class file
  • reverse sort order

Links:

• • • ISuperhero exercise code solution (HW)
    • Class code: is, is , casting using (type)object
    • Class code: IComparable, IComparer
    • Lesson Summary Video
    • Homework!
    • IComparable – MSDN link
    • IComparer – MSDN link
    • Array sorting algorithm – MSDN link
    • Array sorting algorithm – Stackoverflow

   

We learned about properties in C#. in the second part of the class we learned about interfaces in C#. we investigated objects using:  is, as, null  key-words

More topics covered:

• • static class and static ctor
  • properties access modifiers, backing field, abstraction
  • marker interface
  • interface inheritance
  • interface default access modifiers
  • is, as
  • null

Links:

• • • Class code: properties example
    • Class code: Fruit properties exercise Solution
    • interfaces – MSDN link
    • Lesson Summary Video
    • Homework!