Transcript Document

C# Data Structures
AND Generics
By Michael and Miles
Overview
What are data structures?
Benefits and uses
What are generics?
Benefits and uses
Live samples
Summary
Data Structures
1.
2.
3.
4.
Collections of data
Fetch and store
type of data structure depends on situation
Examples
Array, arraylist, list, linkedlist, stack,
queue, dictionary, etc.
5. Most basic is the array
Arrays
1. Most commonly used data structure
2. Contents are stored in contiguous memory
3. All data must be same type
Pros:
Quick direct access (for loop)
Easy to use
Cons:
Searching is proportional to data size
Cannot resize array
What are generics?
1. One of the most powerful features
introduced in C# 2.0
2. System.Collections.Generic…
3. Mainly used with collections/data structures
4. Type safety
5. Generic methods
1. Similar operations on different data types
1. Pros
• Type safety
• Reduces the need for type casting
– less run-time errors
• Performance boost
– No boxing/unboxing (less code)
• maximize code reuse
2. Cons
• Can get complex
• Learning curve
List<T>
1.
2.
3.
4.
Similar to arrays –
A generic data structure
Type-safe
Dynamic resizing - .Add() .Insert()
.Remove()
5. Built in search methods
6. flexibility
Queues
Like a circular array
First come first serve
Insertions made at the tail
Pros:
Good for processing
Cons:
Not searchable
Not many uses
Dictionaries
Key value pairs
Data is unordered
Easy lookups
Type safe (generic)
Drawbacks of non-generic
data structures
Data stored as type object
– Casting: conversion of data types
double x = 1234.7;
int a;
a = (int)x; // cast double to int
– Limited type checking *
Increased Overhead
– More work to getting something done
“CANNOT IMPLICITLY CONVERT
TYPE OBJECT TO INT”
And then there’s LINQ
Write queries (similar to SQL queries)
Retrieve info from many data structures
– Arrays, List<> etc.
Quick example
http://msdn.microsoft.com/en
-us/library/bb907066.aspx
Summary
Types of Structures
Generics
– What they are/how to use
Practical uses
Questions/
comments/
compliments?