Project 9 – Data Structures and Data Representation

List of Terms

• Global Variable – A variable that is non-local, and can be accessed within different functions of the program.
  
• Local Variable – A local variable is a variable that can only be accessed from within the function in which it was declared.
  
• Elementary Data Types:
  
  • Character – a character is a unit of information that corresponds to symbol (alphabet, number, or common punctuation).
    
  • String – a sequence of characters.
    
  • Integer – refers to a data type which is a subset of whole numbers (non-fractions).
    
  • Floating – a float data type stores floating-point numbers with up to 17 significant digits, and corresponds to IEEE 4-byte floating point.
    
  • Boolean – is a data type which can have either a true or false value.
    
• Data Identifier – is a name given to a data element (character string or symbol) within a data dictionary (registry), which usually consists of at least 3 parts: Object, Property, and representation term.
  
• Data Type – is a classification, naming one of the different types of data that states the possible values for that type, what can be done to it, and the values that it can store.
  
• Memory Address – identifies the memory location where a program can store and access data.
  
• Actual Data –
  
• Variable – is the name given to a known or unknown value. Unlike in mathematics (in which a variable represents a range of numbers), a programming variable can only represent a single value at any given moment.
  
• Literal – signifies a fixed value.
  
• Constant – is a variable that cannot be altered by the program during execution. While it is stated once, it can be referenced multiple times.
  
• Number Base Systems – a system for expressing numbers using symbols in a consistent manner, determined by the base or radix.
  
• Base 2 – (binary numeral system) represents numeric values with either 0 or 1 as its symbols. This system is used by all modem computers.
  

Decimal	Binary
0	0
1	1
2	10
3	11
4	100
5	101
6	110
7	111
8	1000
9	1001
10	1010
11	1011
12	1100
13	1101
14	1110
15	1111
16	10000

10000 (Binary)

= [(1) x 2^4] + [(0) x 2^3] + [(0) x 2^2] + [(0) + 2^1] + [(0) + 2^0]

= [2 x 2 x 2 x 2] + [0] + [0] + [0] + [0]

= 4 x 4

= 16 (Decimal)

 

• Base 10 – (decimal numeral system) in which all numbers, no matter how big or small, can be represented by 0, and 1 through 9. It also uses +/- to show if it is greater than or less than 0.
  
• Base 16 – (hexadecimal) is a numeral system with a base of 16. It uses the numbers 0 through 9, and the alphabetical characters A through F to represent values 10 – 15.
  

Dec.	Hex.	Dec.	Hex.	Dec	Hex
0	0	16	10	100	64
1	1	17	12	255	FF
2	2	18	13	256	100
3	3	19	14	1000	3E8
4	4	20	15	4095	FFF
5	5	21	16	4096	1000
6	6	22	17	10000	2710
7	7	23	18
8	8	24	19
9	9	25	1A
10	A	26	1B
11	B	27	1C
12	C	28	1D
13	D	29	1E
14	E	30	1F
15	F	31	20

10000 (Hexidecimal)

= [(1) x 16^4] + [(0) x 16^3] + [(0) x 16^2]+ [(0) x 16^1] + [(0) x 16^0]

= [65536] + [0] + [0] + [0] + [0]

= 65536 (decimal)

 

• Floating Point – or floating point, is a system for displaying numbers that are too large or small to be displayed as integers.
  
• Relative Addressing –
  
• Data Types and Data Abstaction
  
  • File – an object containing the information to control a stream.
    
  • Record – is a data type used to describe the values and variables contained in a struct.
    
  • Array – is a data type that describes a series of elements of the same type, that are selected from one or more indices, by the program.
    
    • Single Dimension – array is a data grouping of multiple values that can be referenced with a single identifier.
      
    • Multi Dimension – arrays are a set of 2 or more arrays within an array
      
• Language Statements
  
  • Natural Language Statements/Grammar and Logic
    
  • Artificial Language Statements/Syntax and Semantics
    
  • Input/Output Statements – Instruct the computer to read and process information from an input deveice and/or send the information to an output device.
    
  • Assignments Statements – sets or resets the current value of a variable, field, parameter, or element.
    
  • Program Design Language (PDL) – Meta Language
    
    • Syntax Diagrams – represent Context Free Grammar
      
    • BNF (Backus-Naur Form) – a technique for notating context-free grammars, used to describe syntax diagrams.
      
  • Elementary Language Statements and Structured Language Statement
    
    • Assignment and Unconditional Statements
      
    • Selection and Looping Statement
      
• Expression Components
  
  • Operators, Operands and Results
    
    • Unary – an operation with only one input (A).
      

      
       

      f: A → A
      

      
       

      Examples of this are:
      

Increment:	++x, x++
Decrement:	−−x, x−−
Address:	&x
Indirection:	*x
Positive:	+x
Negative:	−x
One's complement:	~x
Logical negation:	!x
Sizeof:	sizeof x, sizeof(type-name)
Cast:	(type-name) cast-expression

 

• Binary – an operation involving two inputs (A, B). This can be found in Arithmetic equations such as add, subtract, divide, multiply, etc.
  

• Simple Types
  
  • Arithmetic – Basic mathematical operations (+,-,*,/,^)
    
  • Logical – is a data type which can have either a true or false value.
    
  • Relational – matches data based on similar characteristics.
    
• Result
  
  • Unconditional (Not Boolean)
    
  • Conditional (Boolean)
    
    • True
      
    • False