Section 1 - Fundamentals of Programming

Question 1

What is an algorithm?

Answer 1

A set of rules/a sequence of steps you can follow to solve a problem. They have inputs, processing and outputs.

Question 2

What is psuedocode?

Answer 2

The midpoint between a natural language and a programming languages. There are no concrete rules or syntax with multiple ways of writing the same statement.

Question 3

What does the trunc function do?

Answer 3

Rounds a real number down to the nearest whole number

Question 4

What does the div function do?

Answer 4

Floor division

Question 5

What does the mod function do?

Answer 5

Gives the remainder

Question 6

What are variables?

Answer 6

Identifiers given to memory locations whose content will change during the course of the program

Question 7

What are constants?

Answer 7

A type of variable where the value never changes as the program is being run

Question 8

What is the advantage of using constants?

Answer 8

• There is no chance a programmer accidentally changes it’s value during the program
• It is more readable than using values
• If you change the value of the constant you don’t have to manually change it on every line it appears

Question 9

What are the 3 programming constructs?

Answer 9

• Sequence
• Selection
• Iteration

Question 10

What is sequence?

Answer 10

2 or more statements following one after the other

Question 11

What is selection?

Answer 11

A statement used to select which statement will be executed next, depending on some condition

Question 12

What are relational operators used for?

Answer 12

Formulating the condition for selection

Question 13

What is the CASE statement?

Answer 13

An alternative structure to the IF statement that is useful when there is a choice between several alternatives

Question 14

What is the XOR operator?

Answer 14

Exclusive OR, i.e either a or b but not both

Question 15

What is an iterative statement?

Answer 15

A statement causing the code to perform a loop, repeating a number of statements

Question 16

What is indefinite iteration?

Answer 16

Where the iteration continues until a specified condition is met

Question 17

What is definite iteration?

Answer 17

Where the number of loops is decided in advance

Question 18

What is the difference between a WHILE loop and a REPEAT UNTIL loop?

Answer 18

In a while loop the condition is checked at the start so will iterate 0 or more times, whilst a REPEAT UNTIL loop is checked at the end so will always iterate at least once

Question 19

What is a data structure?

Answer 19

A collection of elementary data types with built-in methods to facilitate processing in some way

Question 20

What is an array?

Answer 20

A finite, ordered set of elements of the same data type. Finite means there is a set number of elements in the array whilst ordered implies there is a first, second, third, etc

Question 21

How can you reference each element of an array?

Answer 21

By using an index (usually starting at 0)

Question 22

What is a tuple?

Answer 22

An ordered list of elements

Question 23

What is a n-dimensional array?

Answer 23

A set of elements of the same data type, indexed by a tuple of n integers

Question 24

What is a subroutine?

Answer 24

A named block of code which performs a specific task within a program

Question 25

What are the 2 common types of subroutines?

Answer 25

- Functions - Procedures

Question 26

What is the difference between functions and procedures?

Answer 26

Functions always assign a return value to a variable and is called like an input, where as a procedure is called by just writings its identifier and does not need to return a value

Question 27

How can you pass parameters into a subroutine?

Answer 27

- By value, meaning changing the parameter inside the subroutine will not affect its value in the rest of the code - By reference, where the address of the parameter and not its value is passed into the subroutine and therefore any changes will reflect in the rest of the code

Question 28

What are global variables?

Answer 28

The default state for a variable, able to be used anywhere in the program

Question 29

What are local variables?

Answer 29

Variables declared in a subroutine that cannot be accessed outside of it. A local variable can share a name with global variables or other local variables inside different subroutines

Question 30

Why should you declare local variables?

Answer 30

It makes each subroutine is self-contained and independent of global variables.

Question 31

What is modular programming?

Answer 31

Where a program is broken into different subroutines

Question 32

What are the advantages of modular programming?

Answer 32

- They are small enough to be understandable as a unit of code, making it easier to understand, debug and maintain them - They can be tested independently, reducing the time needed to make a program - It can be reused in different programs or different parts of the same program - When working in a group each programmer can handle 1 subroutine at a time

Question 33

What is required in order to store data permanently?

Answer 33

It must be stored in a file or disk

Question 34

What is a file?

Answer 34

Structured data, usually consisting of many records

Question 35

What is a record?

Answer 35

A data structure containing a number of fields, each holding an item of data

Question 36

How can you overwrite data in an existing file?

Answer 36

You open the record for both reading and writing in order to search through the record before writing a new record in place

Question 37

What is the advantage of a binary file?

Answer 37

It can contain records with different types of data types in each field

Question 38

What is exception handling?

Answer 38

The process of dealing with unexpected conditions in your program

Question 39

What are common errors that can cause a program to crash?

Answer 39

- Trying to read a non-existent file - Trying to convert a non-numeric string to an integer or real - Trying to perform calculations with a non-numeric value - Division by 0