Basics Of Programming

Question 1

What is Computer Science?

Answer 1

The study of computer software, algorithms and efficiency

Question 2

Sequence of problem solving?

Answer 2

1) Understand the problem?
- What are the knowns and unknowns?

2) Plan how to solve the problem
- What algorithm is used to solve the problem
- What assumptions are being made?
- Is this similar to other problems?
- can the problem be split into parts?

3) Carry out your plan
- Write programs to implement algorithms?

4) Asses the result
- Does the program conform to the algorithm?
- Does the program/algorithm solve the problem?
- Is the program correct for the cases?

5) Describe what you have learnt
- So you do not make the same mistakes again

6) Document the solution
- Write a report for the uses of the program
- Write comments within the program

Question 3

What is an algorithm?

Answer 3

Set of steps to accomplish a task

(Everyday tasks require algorithms i.e brushing teeth)

Question 4

What characteristics must algorithms have?

Answer 4

Must be precise so:
- repeatable
- have a predictable outcome
- can be executed by different people

Question 5

Elements of an algorithm

Answer 5

Sequence - Each step is followed by another step

Selection - a choice may be made among alternatives

Iteration - set of steps may be repeated

Question 6

What is a program?

Answer 6

A set of instructions given to a computer, corresponding to an algorithm to solve a problem

Question 7

How does a program work?

Answer 7

1) Ingest information from the real world

2) Process data internally

3) Send computed data back to real world

Question 8

What is: - Print
- “Hello World”

An example of?

Answer 8

Print - Function

Hello world - Argument

Question 9

What is a function?

Answer 9

A common task we can reuse

Question 10

Syntax vs Logic error

Answer 10

Syntax - When the program doesn’t conform to the required structure
[ Print spelt incorrectly = PROGRAM WONT START ]

Logic - When the program runs but doesn’t work as expected
[ Must test it]

Question 11

What does:

\a
\b
\n
\t
\’
\”

Produce?

Answer 11

• Bell
• Backspace
• Newline
• Tab
• Single Quote
• Double Quote
• Character

Question 12

Integer vs Floating point

Answer 12

• Whole number with no fractional part = Integer
• Number with fractional part (not extremely precise) = Floating

Question 13

How to do:

Addition
Subtraction
Division
Multiplication
Modulus
Integer Division
Power
What are they examples of?

Answer 13

/
*
% 5%2 =1
//
** a**b

Question 14

Precedence of operators

Answer 14

( ) = High
* / % = Middle
+ - = Low

Question 15

What is an identifier?

Answer 15

Used to name parts of code
(I.e print)

• Start with _ or letter, followed by more
• Prefered: hello_World or my_first_program

Reserved words: if, else, for

Question 16

What are variables?

Answer 16

Sections of memory where data can be stored

I.e a_value = 10

Question 17

What is a comment?

Answer 17

Part of code (Starting with #) that is ignored by python and intended to help a human reader

Question 18

What is a string literal / j Eric literal?

Answer 18

Fixed character sequences [“Hello]

Numbers used directly [3.15]

Question 19

What is syntax?

Answer 19

The fundamental rules of a programming language

Question 20

Wayne Napolo

Identify:

from math import sqrt
Side1 = 3.5 + 7.2
Side2 = 4.5
Hypotenuse = sqrt(side1side1) +(side2side2)

Print(“The hypotenuse is “, hypotenuse)

Answer 20

1) [#Wayne…] = Comment
2) [= 3.5 + 7.2] = Expression
3)[hypotenuse =] = variable
4)[sqrt] = function
5)[=4.5] = numeric literal
6)[”The hypotenuse is “] = string literal
7)[[ , hypotenuse] = Parameters