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General Discussion

19 January, 2016 - 11:41

Our interactions (inputs and outputs) of a program are treated in many languages as a stream of bytes. These bytes represent data that can be interpreted as representing values that we understand. Additionally, within a program we process this data in various ways such as adding them up or sorting them. This data comes in different forms. Examples include: yourname which is a string of characters; your age which is usually an integer; or the amount of money in your pocket which is usually a value measured in dollars and cents (something with a fractional part). A major part of understanding how to design and code programs in centered in understanding the types of data that we want to manipulate and how to manipulate that data.

"A type defnes a set of values and a set of operations that can be applied on those values. The set of values for each type is known as the domain for that type." 1 The four major families of data include:

  • Nothing
  • Integer
  • Floating-point
  • Complex

The C++ programming language identifes five data types as standard data types:

  • Void
  • Boolean
  • Character
  • Integer
  • Floating-point

The standard data types and the complex data types within C++ have a series of attributes, which include:

  • C++ Reserved or Key Word
  • Domain the allowed values
  • Signage do they allow negative numbers or only positive numbers
  • Meaning i.e. What do they represent
  • Rules of Definition What special characters indicate the data type
  • Size in terms of the number of bytes of storage used in the memory
  • Operations Allowed i.e. Which operators can I use on the data type

Placing some of the above into a summary table, we get:

Table 3.1 A summary table

Family

Data Type

Reserved Word

Represents

Standard Type

Nothing

Null or nothing

void

No data

Yes

Integer

Boolean

bool

Logical true and false

Yes

Integer

Character

char

Single characters

Yes

Integer

Integer

int

Whole numbers

Yes

Floating Point

Floating Point

float

Fractional numbers

Yes

Complex

String

string

A sequence (sting them along) of characters

No

Complex

Array

N/A

A collection of elements of the same data type

No

Complex

Pointer

N/A

A value that points to a location (an address) within the data area

No

The five standard data types usually exist in most programming languages and act or behave similarly from language to language. Most courses of study for a programming course or language will explain the standard data types first. After they are learned, the complex data types are introduced.

The Boolean, character and integer data types are identifed as belonging to the Integer Family. These data types are all represented by integer numbers and thus act or behave similarly.