Collections und Generics

Transkript

1 Collections und Generics Proseminar Objektorientiertes Programmieren mit.net und C# Nadim Yonis Institut für Informatik Software & Systems Engineering

2 Agenda Collections Standard Collections Comparer Generics Generic Collections Iterators Collections und Generics 2

3 Hierarchy System.Object Reference Types Value Types System.ValueType All Base Class, Library classes and interfaces, including:...etc. All structs, including built-in numeric types System.Int32 System.Boolean...Etc. System.String System.Array System.Collections System.Collections.Generic Collections und Generics 3

4 Collections Container Usually contains elements of the same type Dynamic Collections und Generics 4

5 Collections Container Usually contains elements of the same type Dynamic Standard Collections Collections und Generics 5

6 Collections Container Usually contains elements of the same type Dynamic Standard Collections Generic Collections Collections und Generics 6

7 Collections Collection Index based Key/value pair Prioritized Collection Specialized Collection Array Hash table Stack String Collection List SortedList Queue Hybrid Dictonary Collections und Generics 7

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10 Interfaces Interface Purpose ICollection Defines size, enumerators and synchronized methods for all collections IEnumerable Exposes the enumerator, which supports a simple iteration over the collection IList Represents a collection of objects that can be individually accessed by index IDictionary Represents a collection of key/value pairs Collections und Generics 10

11 Hierarchy IEnumerable ICollection IList IDictionary Collections und Generics 11

12 ArrayList Collections und Generics 12

13 ArrayList Collections und Generics 13

14 ArrayList Collections und Generics 14

15 ArrayList Collections und Generics 15

16 Interface Purpose ICollection Defines size, enumerators and synchronized methods for all collections IEnumerable Exposes the enumerator, which supports a simple iteration over the collection IList Represents a collection of objects that can be individually accessed by index IDictionary IComparer Represents a collection of key/value pairs Exposes a method that compares two objects Collections und Generics 16

17 Comparer Collections und Generics 17

18 Standard vs Generic Collections Standard Collections manage objects Using Generic Collections is generally recommended Immediate benefit of type safety Better Performance when elements are value types (no need for boxing) Code is easier to read Collections und Generics 18

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21 Generics Java Generics only exist in source code Java Compiler 'Erases' the generic type information.net Generics are implemented at runtime Generic type information is not lost Collections und Generics 21

22 ...Etc Collections und Generics 22

23 Collections und Generics 23

24 System.Object Reference Types All Base Class, Library classes and interfaces, including: System.String System.Array System.Collections...Etc. System.Collections.Generic Collections und Generics 24

25 Interfaces Interface Purpose ICollection<T> Defines size, enumerators and synchronized methods for all collections IEnumerable<T> Exposes the enumerator, which supports a simple iteration over the collection IList<T> Represents a collection of objects that can be individually accessed by index IDictionary<TKey,TValue> Represents a collection of key/value pairs Collections und Generics 25

26 Iterators Method or operator that enables developers to support foreach iteration in a class or struct without having to implement the IEnumerable interface Collections und Generics 26

27 Iterators Collections und Generics 27

28 Iterators Collections und Generics 28

29 Iterators : IEnumerator Collections und Generics 29

30 Iterators : IEnumerator Collections und Generics 30

31 Iterators : IEnumerator ToDo: Implement methods MoveNext and Reset and property Current Collections und Generics 31

32 Yield Collections und Generics 32

33 References Jay Hilyard & Stephen Teilhet, 'C# Kochbuch', 2006 Jesse Liberty, 'Programmieren mit C#', 2005 Krzystof Cwalina & Brad Abrams, 'Richtlinien für das Framework-Design', Proseminar Objektorientiertes Programmieren mit.net und C# Nadim Yonis Institut für Informatik Software & Systems Engineering Collections und Generics 33