Topics 1-3

Question 1

What’s a high-level language?

Answer 1

Designed for humans, easier to learn/use.Incl. libraries of pre-built automations (‘functions’). E.g. Python, Java, C++.
Must be translated into machine language for CPU to understand.

Question 2

What’s a low level language?

Answer 2

Close to what computer speaks, difficult for humans to read. Include assembly languages & machine code.

Question 3

What is an Interpreter?

Answer 3

Translates high-level language into machine code one instruction at a time, immediately executes that instruction, then moves to the next & repeats.
No intermediate Program is saved.

Question 4

What is a Compiler?

Answer 4

Translates complete high-level program into machine language program. Complete translation before execution. Result can be executed repeatedly without further translation.

Question 5

5 steps in the Program Development Cycle?

Answer 5

1. Design the program
2. Write the code
3. Correct syntax errors
4. Test the program
5. Correct logic errors

Question 6

Explain 2 ways to design/visualise a program:

Answer 6

Using Pseudocode (describing steps in plain speech as though to a person).
With a Flowchart diagram.

Question 7

What is Pseudocode?

Answer 7

Pseudocode is a model computer program written in informal language that has no syntax rule

Question 8

What 3 step process does a computer program usually follow?

Answer 8

Input | processing | output
Input: data received by program while running.
Processing: Perform operation on input (e.g. mathematical calculation).
Output: Produce desired information/response.

Question 9

Instruct python to produce an output using the ____ function.

Answer 9

print(desired output)

Question 10

How can I explain what’s going on in my code?

Answer 10

Comments are identified with a leading hash character. Python ignores everything to right of this on the line. Used to explain & identify components of the program for yourself & future users

Question 11

Why use comments?

Answer 11

Comments (Python; indicated by leading hash character) are ignored by translator program; meant for humans. Offer explanation of parts of the program, enabling easier understanding, editing etc. For others and yourself, when you come back later.

Question 12

How can I enter multi-line comments?

Answer 12

’’ Triple quotation marks:’’’
“”” These are used often to document the code; e.g. right at the top of a program describing functions, inputs & outputs”””

Question 13

What’s a variable?

Answer 13

A value stored in the computers memory; that the program can store, update & retrieve.

Question 14

variable = data… what is the equals sign here?

Answer 14

The assigment operator. It creates and/or updates the variable, named/addressed with vaue to its left, and assigning it the value to its right.

Question 15

Python has strict variable naming rules:

Answer 15

Variable names:
- cannot be a Python keyword
- cannot contain spaces (use underscores for variable_name)
- first character must be a letter or an underscore
- otherwise contain only letters, digits, or underscores
- are case sensitive.

Question 16

What variable data types have we learned?

Answer 16

int – for positive and negative integer numbers.
float – for positive and negative real numbers.
str – for character strings.
bool - boolean yes/no value

Question 17

How does the interpreter assign data type for a numeric literal? (A number written in the program.)

Answer 17

Presence of a decimal point. ‘2.0’ = float. ‘2’ = integer.

Question 18

Will this work?
….
if statement
print(‘string’)
…

Answer 18

No! Missing the colon after the if statement.
If statement:

Question 19

Are these variables different?
number_input
Number_input

Answer 19

Yes, variable names are case sensitive.

Question 20

What’s special about this variable?
NUMBER_INPUT

Answer 20

by convention, variables in all caps are ‘constants’; unchanged during program run. Reduces possible errors - enter value only once.
May be changed before running (e.g. reserve bank interest rate, needs updating in code when changed).

Question 21

Shape meaning in flowchart:
Rectangle?

Answer 21

Process - an instruction to be carried out by the program.

Question 22

Shape meaning in flowchart:
Parallelogram?

Answer 22

Input/output - represents entry by user or display of data by the program.

Question 23

Shape meaning in flowchart:
Diamond?

Answer 23

Selection/Decision structure (if condition, then action…)`

Question 24

Shape meaning in flowchart:
Oval?

Answer 24

Terminal - indicates start and end of a program.

Question 25

What’s the difference between Iterations, Repetitions & Loops?

Answer 25

None. All interchangeable terms for ‘circular’ structures used to handle repetitive tasks in programs.

Question 26

What do passwords have to do with loops?

Answer 26

Password entry is a data validation loop. While input != password, keep looping through ‘sorry, that wasn’t correct, try again’.