Programming Elements

Question 1

Identifier

Answer 1

A unique name for something (e.g. variable, constant, procedure, etc.) within the program

Question 2

Variable

Answer 2

An identifier associated with a specific memory location, used to store data. Its value can change while a program runs

Question 3

Constant

Answer 3

A named value within a program with a fixed value that does not change while the program runs

Question 4

What are the benefits of declaring a constant? (2)

Answer 4

1. When its value changes, only the declaration has to be changed
2. It makes your code easier to read, debug and maintain

Question 5

Why aren’t variable names beginning with underscores encouraged?

Answer 5

A considerable number of names beginning with underscores are already reserved for use by the system

Question 6

Data type

Answer 6

The type of data stored in a variable

Question 7

What does the data type of a variable define? (3)

Answer 7

1. The type of data stored in a variable
2. How much memory is needed to store it
3. The operations that can be performed on it

Question 8

Integer

Answer 8

Data type for whole numbers

Question 9

Real OR Float

Answer 9

Data type for fractional numbers

Question 10

Character

Answer 10

Data type for a single character

Question 11

String

Answer 11

Data type for text (over 1 character). Sometimes limited to a length of 255 characters

Question 12

Boolean

Answer 12

A true or false value

Question 13

How much memory is typically needed to store:

1. An integer?
2. A float?
3. A single character?
4. A boolean?

Answer 13

1. 2 or 4 bytes
2. 4 or 8 bytes
3. 1 byte
4. 1 byte, although 1 bit would suffice

Question 14

Assignment

Answer 14

When a variable is given a value

Question 15

Initialisation

Answer 15

Explicitly setting the starting values of variables

Question 16

Algorithm

Answer 16

A series of instructions that solves a specific problem

Question 17

What are the three main parts of program flow control?

Answer 17

1. Sequence
2. Selection
3. Iteration

Question 18

Sequence

Answer 18

Where instructions are executed one after another in series

Question 19

Selection

Answer 19

Where the program executes certain instructions based on a condition

Question 20

The two basic selection constructs are…

Answer 20

1. If/else statements
2. Case statements*

*Do not exist in Python

Question 21

Boolean expression

Answer 21

An expression that evaluates to true or false

Question 22

Logical operators

Answer 22

NOT, AND, OR and XOR. Used in conditions and Boolean expressions.

Question 23

Relational operators

Answer 23

Operators that compare two values

Question 24

Iteration

Answer 24

Where a program executes a group of instructions zero or more times based on a condition

Question 25

What are the three types of iteration loop constructs?

Answer 25

1. While
2. Repeat/until*
3. For

*Do not exist in Python

Question 26

How many times does each loop construct run?

Answer 26

While loops: zero or more times
Repeat/until loops*: at least once
For loops: a specific number of times

*Do not exist in Python

Question 27

Condition

Answer 27

A Boolean expression that controls an iteration or selection statement

Question 28

Structure chart

Answer 28

A diagram showing how a code module breaks down into smaller modules through sequence, selection and iteration

Question 29

Flowchart

Answer 29

A diagram using commonly defined symbols to express an algorithm

Question 30

Pseudocode

Answer 30

A way of writing an algorithm using programming constructs, but not in an actual language