Programming

Question 1

What are the 3 basic programming constructs?

Answer 1

Sequence - the order of instructions
Selection - an instruction is only carried out if a condition is met (if, elif, else)
Iteration - looped section of code

Question 2

What are the 2 types of iteration?

Answer 2

Definite iteration - count controlled (for)
Indefinite iteration - condition controlled (while, repeat until)

Question 3

What is nested iteration?

Answer 3

When a loop is included inside another loop

Question 4

What is nested selection?

Answer 4

When more than one decision needs to be made when carrying out a task

Question 5

What is nesting?

Answer 5

The process of including one programming construct within another

Question 6

What is a variable?

Answer 6

A named piece of memory which contains a value that can change.

Question 7

What is an identifier?

Answer 7

The name of a variable?

Question 8

What is declaration?

Answer 8

Giving a variable a name or giving a value to a constant

Question 9

What is assignment?

Answer 9

Giving a variable a value

Question 10

What is a constant?

Answer 10

A named piece of memory which holds a value that cannot change.

Question 11

What is scope?

Answer 11

Refers to where a variable, constant, function or procedure can be used - it can be either local (within a subroutine) or global (the whole program)

Question 12

What are the 5 data types?

Answer 12

Integer - number
String - text
Boolean - true/false
Character - a singular letter/number
Float/ float - decimal

Question 13

What is casting?

Answer 13

The process of changing the data type of a variable e.g. int(‘54’) returns 54

Question 14

What are the arithmetic operators?

Answer 14

*
/
DIV (//)
MOD (%)

Question 15

What are the relational operators?

Answer 15

Used for assignment and comparison:
= - assignment
== - equivalence
< - less than
<= - less than or equal to
> - greater than
>= greater than or equal to
!= - not equal to

Question 16

What are the Boolean operators?

Answer 16

AND
OR
NOT

Question 17

What is an array?

Answer 17

A data structure that holds similar, or related data (a list). Each element has a position (index) within the array and holds a value. They must all be of the same data type.

Question 18

How is an array declared?

Answer 18

A programmer gives it 2 properties:
An identifier and
A size

Question 19

How is a 2d array declared?

Answer 19

With an identifier and 2 values - a row and a column

Question 20

How can you determine the length of a string?

Answer 20

len()

Question 21

How can you determine the position of a character in a string?

Answer 21

string[0]
where string = the variable and 0 = the position

Question 22

What is a substring?

Answer 22

A set of characters that exists inside of a string.

Question 23

How can a random number be generated?

Answer 23

import random
random.randint(range)

Question 24

What is a subroutine?

Answer 24

A smaller piece of named code that exists within a larger program - its purpose is to perform a specific task.
(using these is sometimes called structured programming!)

Question 25

Why are subroutines useful?

Answer 25

They are smaller in size - thus easier to debug + to understand + they save time as the programmer doesn’t have to write out the whole code, just the identifier
They make the program code shorter

Question 26

What are 2 types of subroutine?

Answer 26

Procedures
Functions

Question 27

What is a procedure?

Answer 27

A subroutine that performs a specific task - it does not return a value when called

Question 28

What is a function?

Answer 28

A subroutine that also performs a specific task, except it manipulates data, and returns a value to the main program

Question 29

What is a parameter?

Answer 29

A variable within a subroutine

Question 30

What is the purpose of robust and secure programming?

Answer 30

Making sure the correct data type is entered (validation)
Making sure the correct person is using the program (authentication)
Debugging (testing)

Question 31

What are the 5 validation checks?

Answer 31

Range check - Does the input fall within the specified range?
Length check - Is it a sensible length?
Presence check - Is something entered at all?
Format check - Is it in the correct format e.g DD/MM/YY
Type check - Is it the correct data type?

Question 32

What are the 3 types of test data?

Answer 32

Normal data
Boundary data - data on either end of the accepted range (e.g if its 1,2,3 - boundary would be 1 and 3 (valid) as well as 0 and 4 (invalid)
Erroneous data - data that the program should not accept

Question 33

What is a logic error?

Answer 33

An error related to the structure of the program

Question 34

What is a syntax error?

Answer 34

An error related to the grammar and the rules of the programming language e.g typing PRINT in all caps

Question 35

What is source code?

Answer 35

A set of instructions written in a human readable language

Question 36

What is high level programming language?

Answer 36

Language typed directly into the machine which is close to the natural language of humans

Question 37

Why is high level programming language used over low level programming language?

Answer 37

It is easier to understand than machine code
It is easier to debug
It provides built in subroutines
It is shorter

Question 38

What is low level programming language?

Answer 38

Languages that sit close to the computer’s instruction set e.g. machine code and assembly language