Chapter 7

Question 1

Algorithm

Answer 1

A series of steps to solve a problem. Can be expressed in structured English, pseudocode or as a flowchart (also called flow diagram).

Question 2

Flowchart/Flow Diagram

Answer 2

A diagram using commonly defi ned symbols to express an algorithm.

Question 3

Structured English

Answer 3

A way of writing an algorithm in natural language using some basic programmingconstructs such as IF…THEN…ELSE and loops. More structured than just natural language/prose.

Question 4

Pseudocode

Answer 4

A way of writing an algorithm that is close to actual programming language, usingcoding-style constructs such as IF…THEN…ELSE, loops and array notation as appropriate.

Question 5

Hungarian Notation

Answer 5

The convention of prefi xing identifiers to indicate what type of object they are.Commonly used with forms where, for example the prefix txt might indicate a textbox and lst might prefix a list box. The prefix is conventionally in lowercase.

Question 6

camelCase

Answer 6

The use of capital letters in an identifier to make them more readable. With camelCase the first word is not capitalised:txtCustomer, lstCounty, frmAddCustomer, btnSubmit

Question 7

PascalCase

Answer 7

The use of capital letters in an identifier to make it more readable. For example,variable and procedure identifiers: StudentNumber, ProductID, StartPoint, CalcTotal

Question 8

(programming) Sequence

Answer 8

Where instructions are executed one after another in series.

Question 9

(programming) Selection

Answer 9

Where the program will execute certain instructions based on conditions. Selectionstatements include: IF…THEN…ELSE and CASE…OF to select which commands to execute.

Question 10

(programming) Iteration

Answer 10

Where a program will execute a group of instructions zero or more times based on a condition. FOR loops will execute instructions a specific number of times, REPEAT…UNTIL loops one or more times and WHILE…DO loops zero or more times.

Question 11

(programming) Condition

Answer 11

A boolean expression that controls an iteration or selection statement. Forexample, REPEAT…UNTIL X=10, where X=10 is the condition.

Question 12

(programming) Boolean Expression

Answer 12

An expression that is true or false. For example: continue=”Y”Expressions can be more complex, containing several parts: ((continue=”Y”) or (continue=”y”)) and (tries

Question 13

High Level Programming Language

Answer 13

A programming language where programming constructs are written in a waythat is close to natural language instead of in mnemonics or machine code. For example, Delphi, Pascal, Visual Basic, Java, C++.

Question 14

Imperative Language

Answer 14

Programming language such as Python or Delphi which uses a sequence of statements to determine how to reach a certain goal or solve a problem.

Question 15

Assembly Language

Answer 15

Second generation programming language where instructions are in the form ofmnemonics.

Question 16

Mnemonics

Answer 16

Abbreviations representing commands used in assembly language programming.For example, LDA, STO, ADX.

Question 17

Machine Code

Answer 17

First generation code; binary instructions where some bits are used to define theoperation (called the “opcode”) and some bits define the data to be used.

Question 18

Translator

Answer 18

The piece of systems software used to convert different programming languagesinto machine code. Three types: assembler, interpreter and compiler.

Question 19

Interpreter

Answer 19

A translator that converts high level languages into machine code one line at a time, checking syntax, converting to machine code and executing the code.

Question 20

Compiler

Answer 20

A translator that converts high level languages into machine code. Works through the whole program (source code) checking the syntax, then converting to machine code and creating the executable object code, which can be saved. The object code is executed, not the source code.

Question 21

Source Code

Answer 21

The original high level program.

Question 22

Object Code

Answer 22

The executable version of the program after it has been compiled.

Question 23

Assembler

Answer 23

The translator that converts assembly language programs into machine code.

Question 24

Identifier

Answer 24

A unique name for something (variable, constant, program, procedure etc.) withinthe program.

Question 25

Constant

Answer 25

A named value within a program that has a specific value. Its value does notchange while the program is running.

Question 26

Variable

Answer 26

An identifier associated with a particular memory location, used to store data. Itsvalue may change as the program is run and new values are assigned to it.

Question 27

Data Type

Answer 27

A formal description of the type of data being stored in a variable. It defines theamount of memory required and the type of operations that can be performed onthat variable. Typical data types include Integer, real, string, boolean

Question 28

Integer

Answer 28

Data type for whole numbers. Typically uses 2 bytes.

Question 29

Real

Answer 29

Data type for fractional numbers. Typically uses 4 bytes.

Question 30

Char

Answer 30

Data type for a single character. Typically uses 1 byte.

Question 31

String

Answer 31

Data type for text, zero or more characters. Typically uses 1 byte per character.

Question 32

(programming) Operations

Answer 32

The actions that can be performed on a variable.

Question 33

Arithmetic Operations

Answer 33

Add, subtract, multiply, divide, integer division (DIV) and modulus (MOD)

Question 34

Comparison Operations

Answer 34

= =

Question 35

Logical Operators

Answer 35

NOT AND OR

Question 36

Array

Answer 36

A group of data items of the same data type that use a single identifi er. Individualdata items are accessed using a subscript.

Question 37

Syntax

Answer 37

A set of rules that defi nes how program statements must be written in order for the translator to understand them.

Question 38

Syntax Errors

Answer 38

An error in the format of the program statements such as missing semicolons orkeywords spelt incorrectly.

Question 39

Logic Errors

Answer 39

An error in the algorithm that means the outcome is not as expected, even thoughthe program will run.

Question 40

Valid Data

Answer 40

Data that should be allowed by the program. For example, if a range of 1 to 10 isallowed, then valid data will be any number between 1 and 10 inclusive.

Question 41

Invalid Data

Answer 41

Data that is not valid and should be rejected by the program. For example, if arange of 1 to 10 is allowed, then invalid data will include abc, -251, 0, and 11

Question 42

Boundary Data

Answer 42

Data either side of the range extremes. For example in a range of 1 to 10 boundarydata will include 0, 1, 10 and 11