A-Level AQA Computer Science Paper
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Baud Rate>>> The maximum possible number of signal changes that can occur in a wire per second.
Bit Rate>>> The number of bits that can be sent down a wire per second.
Integer>>> A whole number that can be positive, negative or zero.
Examples: -3, 0, 7, 2013588.
Natural (Number)>>> A whole number that is either positive or zero.
Examples: 0, 1, 2, 100, 67238.
Rational (Number)>>> Any number that can be represented as the fraction 'a/b' where 'a' and 'b' are
both integers.
Examples: -0.2, 4/5, 1, 1/3.
Irrational (Number)>>> Any number that cannot be represented as a fraction.
Examples: square root of 2, PI.
Real (Number)>>> Any number that can either be rational or irrational.
Boolean>>> A value that is either true or false.
String>>> A series of characters.
Array>>> A variable that can store multiple values of the same data type.
Example: Storing the high-scores of a game as integers.
,Record>>> A variable that can store multiple values that can have different data types.
Example: Storing data about a book; a string for the title, an integer for the number of pages, etc.
Variable>>> A metaphor for it is that is a box that can store a specific type of item (the data type) and
has a name assigned to it (the identifier). Its value can be changed during run-time of the program.
Constant>>> A metaphor for it is that is a box that can store a specific type of item (the data type) and
has a name assigned to it (the identifier). Its value cannot be changed during run-time of the program.
Subroutine>>> This can be broken down into procedures and functions.
Procedure>>> A block of code that performs a specific task that does not return a value. Parameters can
be passed into it.
Function>>> A block of code that performs a specific task that returns a value. Parameters can be passed
into it.
Selection>>> This is when an if statement or select case is used to, for example, check the value of a
variable.
Iteration>>> This is when, within the program, there is a loop.
Definite Iteration>>> The number of times that the program will loop is already specified.
Example: For loop.
Indefinite Iteration>>> The number of times the program will loop is unknown.
Example: Do loop.
Nested (structures)>>> This is when either iterative or selective statements are put inside of each other.
Meaningful Identifiers>>> Subroutines, variables and objects should have sensible names.
Real Division>>> Finds the value (usually as a decimal) of one number divided by another.
Integer Division>>> Finds the integer part of one number divided by another.
Integer Remainder>>> Finds the remainder of one number divided by another.
Truncation>>> Chops the decimal part off a number.
, Floor>>> Rounds a number down to the nearest integer.
Ceiling>>> Rounds a number up to the nearest integer.
AND>>> Logical Operation:
Returns true only when both values are true.
OR>>> Logical Operation:
Returns true as long as at least one of the values are true.
XOR>>> Logical Operation:
Returns true only when exactly one of the two values is true and not both.
NOT>>> Logical Operation:
Returns true if the value is false and returns false if the value is true.
Exception Handling>>> When a try catch is used in the program to deal with any errors that may occur.
ByVal>>> When a variable is passed into a subroutine as a copy so its value will not be changed.
ByRef>>> When a variable is passed into a subroutine as a reference so its value can be changed.
Local (Variable)>>> A variable that is defined, for example, within a subroutine and cannot be viewed or
modified from outside of the block of code is was declared in.
Global (Variable)>>> A variable that is declared, usually at the start of the program, and can be accessed
and modified from anywhere at all in the program.
Recursion>>> A subroutine's definition contains a self-call meaning a function or procedure calls itself as
a way of performing iteration.
Object-Oriented (Programming)>>> A type of programming paradigm when multiple objects are created
and handled to run the program.
Example: In a game you might have an object for the player and then multiple objects for the enemies.
Procedural (Programming)>>> A type of programming paradigm when you break down a project, usually
using a decomposition diagram, into individual tasks which can each be performed by a procedure.
Functional (Programming)>>> A type of programming paradigm that is mainly used for calculations. No
variables are declared, only functions are used with parameters and return statements.
(Object) Instantiation>>> When an object is first created using the 'new' keyword.
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Baud Rate>>> The maximum possible number of signal changes that can occur in a wire per second.
Bit Rate>>> The number of bits that can be sent down a wire per second.
Integer>>> A whole number that can be positive, negative or zero.
Examples: -3, 0, 7, 2013588.
Natural (Number)>>> A whole number that is either positive or zero.
Examples: 0, 1, 2, 100, 67238.
Rational (Number)>>> Any number that can be represented as the fraction 'a/b' where 'a' and 'b' are
both integers.
Examples: -0.2, 4/5, 1, 1/3.
Irrational (Number)>>> Any number that cannot be represented as a fraction.
Examples: square root of 2, PI.
Real (Number)>>> Any number that can either be rational or irrational.
Boolean>>> A value that is either true or false.
String>>> A series of characters.
Array>>> A variable that can store multiple values of the same data type.
Example: Storing the high-scores of a game as integers.
,Record>>> A variable that can store multiple values that can have different data types.
Example: Storing data about a book; a string for the title, an integer for the number of pages, etc.
Variable>>> A metaphor for it is that is a box that can store a specific type of item (the data type) and
has a name assigned to it (the identifier). Its value can be changed during run-time of the program.
Constant>>> A metaphor for it is that is a box that can store a specific type of item (the data type) and
has a name assigned to it (the identifier). Its value cannot be changed during run-time of the program.
Subroutine>>> This can be broken down into procedures and functions.
Procedure>>> A block of code that performs a specific task that does not return a value. Parameters can
be passed into it.
Function>>> A block of code that performs a specific task that returns a value. Parameters can be passed
into it.
Selection>>> This is when an if statement or select case is used to, for example, check the value of a
variable.
Iteration>>> This is when, within the program, there is a loop.
Definite Iteration>>> The number of times that the program will loop is already specified.
Example: For loop.
Indefinite Iteration>>> The number of times the program will loop is unknown.
Example: Do loop.
Nested (structures)>>> This is when either iterative or selective statements are put inside of each other.
Meaningful Identifiers>>> Subroutines, variables and objects should have sensible names.
Real Division>>> Finds the value (usually as a decimal) of one number divided by another.
Integer Division>>> Finds the integer part of one number divided by another.
Integer Remainder>>> Finds the remainder of one number divided by another.
Truncation>>> Chops the decimal part off a number.
, Floor>>> Rounds a number down to the nearest integer.
Ceiling>>> Rounds a number up to the nearest integer.
AND>>> Logical Operation:
Returns true only when both values are true.
OR>>> Logical Operation:
Returns true as long as at least one of the values are true.
XOR>>> Logical Operation:
Returns true only when exactly one of the two values is true and not both.
NOT>>> Logical Operation:
Returns true if the value is false and returns false if the value is true.
Exception Handling>>> When a try catch is used in the program to deal with any errors that may occur.
ByVal>>> When a variable is passed into a subroutine as a copy so its value will not be changed.
ByRef>>> When a variable is passed into a subroutine as a reference so its value can be changed.
Local (Variable)>>> A variable that is defined, for example, within a subroutine and cannot be viewed or
modified from outside of the block of code is was declared in.
Global (Variable)>>> A variable that is declared, usually at the start of the program, and can be accessed
and modified from anywhere at all in the program.
Recursion>>> A subroutine's definition contains a self-call meaning a function or procedure calls itself as
a way of performing iteration.
Object-Oriented (Programming)>>> A type of programming paradigm when multiple objects are created
and handled to run the program.
Example: In a game you might have an object for the player and then multiple objects for the enemies.
Procedural (Programming)>>> A type of programming paradigm when you break down a project, usually
using a decomposition diagram, into individual tasks which can each be performed by a procedure.
Functional (Programming)>>> A type of programming paradigm that is mainly used for calculations. No
variables are declared, only functions are used with parameters and return statements.
(Object) Instantiation>>> When an object is first created using the 'new' keyword.
