Chapter 1 Introduction

What is a data structure?
       A data structure is a systematic way of organizing and accessing data.

• Primitive data structures:  int, float (double), or char.
• Array: a data structure that store collections of data and allow direct access to the elements by using simple index operations.
• Programming defined data structures:
• Vector: using index operations but it can grow dynamically to meet the runtime demands of the program.
• Stack:  first in last out.
• Queue:  first come first serve.
• Link List: like a chain, store data by pointers.  One can be linked to next or previous one.  This is good for inserting and deleting.
• Tree:  a Parent-Child relation for data.   It is not a linear list.  This is good for searching data.

ADT    Abstract Data Type       (It could be used for any programming language)

• Abstract Data Type is an abstract model that describes an interface between a client (user) and the data.
• ADT defines
• the domain and structure of data
• collection of operations to access the data
• ADT format

• C++ provides the user-defined class type to represent ADT.
• Data values:             data member
• Operations:               member function
• A class consists of two parts:
• private:        data members, internal operations
• public:          constructor function, member function

Five integers Example      Employee Exercise    More Exercise
 
Pointer       example

String         example

"assignment" operator overload:
(Using operator =  instead of strcpy )
We need to use a string class in stead of a character array to implement "assignment" operator overload.
The difference between a string class and a character array is dynamic vs. static size.
You must have an exact array size to implement a character array.  However,
a string uses Null, '\0', to terminate itself.  So, the length of string can be flexible.
We will cover "Dynamic Memory" later.
Click here to see the string class.

Link back to course outline