A-Level AQA Computer Science Paper 2
exam
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.
,A-Level AQA Computer Science Paper 2
exam
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.
,A-Level AQA Computer Science Paper 2
exam
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.
, A-Level AQA Computer Science Paper 2
exam
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.
exam
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.
,A-Level AQA Computer Science Paper 2
exam
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.
,A-Level AQA Computer Science Paper 2
exam
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.
, A-Level AQA Computer Science Paper 2
exam
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.
