4.2.1 Data Structures & Abstract Data Types

What is a data structure?

Containers which store information

—> Differently suited

What is an array?

An indexed set of related elements

What are the characteristics of an array?

• Finite

• Indexed

• Contains elements of the same data type

How is an array declared in C#?

type[ ] arrayName; 

How is information stored by a computer?

As a series of files

File > Record > Field

How is the File class used in C#?

using System.IO;

How do you create a file in C#?

File.Create("FileName.type");

How do you read from a file in C#?

File.ReadAllText("FileName.type");

How do you write to a file in C#?

File.WriteAllText("FileName.type", "__");

What is an abstract data type?

A logical description of how we view data and possible operations

↳ Only concerned with what data is representing, not its construction

What is encapsulation?

Hiding the details of implementation from the user

What is a dynamic data structure?

Collection of data which can grow or shrink in size using a heap

What is meant by a heap?

Portion of memory from which space is automatically (a/de)llocated as required

Where are dynamic data structures useful?

Implementing structures when the maximum size is not known in advance

↳ e.g. queues

What is a static data structure?

Data structure which is fixed in size

—> e.g. arrays

What is an advantage of static data structures?

Pointers do not need to be stored

↳ Saves memory

What is a disadvantage of static data structures?

Memory allocated to it cannot be reallocated, even if it unused