Chapter 8.1 - Programming Concepts

Question 1

five basic constructs and what is included in each

Answer 1

» data use – variables, constants and arrays

» sequence – order of steps in a task

» selection – choosing a path through a program

» iteration – repetition of a sequence of steps in a program

» operator use – arithmetic for calculations, logical and Boolean for decisions

Question 2

Define a variable

Answer 2

a named data store than contains a value that may change during the execution of a program

Question 3

Define a constant

Answer 3

a named data store than contains a value that does not change during the execution of a program.

Question 4

What is it mean to ‘declare’

Answer 4

define the value and data type of a variable or constant

Question 5

How to declare an a constant integer in psuedocode

Answer 5

CONSTANT FirstConst <— 500

Question 6

How to declare a variable thats a string in pseudocode

Answer 6

DECLARE SecondVar : STRING
SecondVar <— “Neel”

Question 7

What does the use of data types enable

Answer 7

» data to be stored in an appropriate way
» data to be manipulated effectively
» automatic validation in some cases.

Question 8

List the basic data types and define each one

Answer 8

» integer – a positive or negative whole number that can be used with mathematical operators

real – a positive or negative number with a fractional part.

char – a variable or constant that is a single character

string – a variable or constant that is several characters in length. Can also be an empty string

Boolean - variable or constant that can have only two values TRUE or FALSE.

Question 9

What does the ‘sequence’ of a program refer to

Answer 9

the order in which the steps in a program are executed

Question 10

What does ‘selection’ of a program refer to

Answer 10

allowing the selection of different paths through the steps of a program

Question 11

2 types of selection statements

Answer 11

IF/ELSE statements
Case Statements

Question 12

Syntax for IF statements for pseudocode

if variable number is greater than 17 print 50 otherwise print 51

Answer 12

IF number > 17
THEN
OUTPUT ‘50’
ELSE
OUTPUT ‘51’
ENDIF

Question 13

When are case statements used

Answer 13

used when there are multiple choices to be made.

Question 14

syntax in psuedocode for caseof statements for addition and subtraction

Answer 14

CASE OF OpValue
“+” : Answer <— n1+ n2
“-“ : Answer <— n1 - n2
OTHERWISE OUTPUT “Please enter a valid choice”
ENDCASE

Question 15

What does ‘iteration’ enable a program to do

Answer 15

allows a section of programming code to be repeated under certain conditions

Question 16

3 types of loops

how many iterations does each have

Answer 16

» Count-controlled loops (for a set number of iterations)

» Pre-condition loops – may have no iterations

» Post-condition loops – always has at least one iteration.

Question 17

What is the count-controlled loop

pseudo code syntax

Answer 17

For loop

pseudocode - FOR …. TO …. NEXT

Question 18

What function is used with for loops in python

what does each parameter stand for
is the last value included or excluded

Answer 18

range (1, 10, 1)

first 1 = starting value
second 10 = end value (EXCLUDED)
last 1 = step value

Question 19

What is the pre-condition loop

pseudo syntax

Answer 19

While loops

WHILE ____ DO

ENDWHILE

Question 20

What is the post condition loop

pseudocode

Answer 20

repeat until loop

REPEAT
____
UNTIL ___

Question 21

When is a condition controlled loop used vs when is a count controlled loop used

Answer 21

Count controlled - number of iterations is known

condition controlled - number of iterations is unknown

Question 22

What is ‘totalling’

Answer 22

keeping a total that values are added to

Question 23

What is ‘counting’

Answer 23

keeping track of the number of times an action is performed

eg number of times a loop is executed

Question 24

4 string functions and purpose

Answer 24

Length - finding the number of characters in the string

Substring - extracting part of a string

upper - converting all the letters in a string to uppercase.

lower - converting all the letters in a string to lowercase.

Question 25

How to use a length string function in

python
pseudocode

Answer 25

python -
len(“Computer Science”)

psueodo-
LENGTH(“Computer Science”)

Question 26

How to use a substring string function in

python
psuedo

Answer 26

python -
“Computer Science”[9:16]
or
MyString[9:16]

Pseudocode-
SUBSTRING(“Computer Science”, 10, 7)
or
SUBSTRING(MyString, 10, 7)

Question 27

First index of strings in
python
Pseudocode

Answer 27

python - 0
Pseudocode- 1

Question 28

How to use an upper string function in

python
psuedo

Answer 28

python -
“Computer Science”.upper()

Pseudocode -
UCASE(“Computer Science”)

Question 29

How to use a lower string function in

python
psuedo

Answer 29

python -
“Computer Science”.lower()

Pseudocode -
LCASE(“Computer Science”)

Question 30

3 diff types of operators

Answer 30

Arithmetic
Logical
Boolean

Question 31

What is an arithmetic operator used for

Answer 31

an operator that is used to perform calculations

Question 32

how to use exponent in python

Answer 32

3 ** 2

3 squared

Question 33

What is a logical operator used for

Answer 33

an operator that is used to decide the path to take through a program if the expression formed is true or false

Question 34

Not equal statement in

python
psuedo

Answer 34

python - !=

pseudocode - <>

Question 35

what is a boolean operator used for

Answer 35

an operator that is used with logical operators to form more complex expressions

Question 36

3 types of boolean operators in python
pseudo

Answer 36

and, or, not

AND, OR, NOT

Question 37

what does it mean to ‘nest’ code

Answer 37

the inclusion of one type of code construct inside another

Question 38

Define a procedure

Answer 38

set of programming statements grouped together under single name that can be called to perform a task at any point in a program.

Question 39

Define a function

Answer 39

set of programming statements grouped together under a single name that can be called to perform a task at any point in a program and will return a value back to the main program.

Question 40

Definition of a parameter

Answer 40

variables that store the values of the arguments passed to a procedure or function

Question 41

How to define a procedure in pseudocode

how to execute

procedure to output a number of stars based on input from user

Answer 41

PROCEDURE Stars (N : INTEGER)
DECLARE C : INTEGER
FOR C <— 1 TO N
OUTPUT”*”
NEXT C
ENDPROCEDURE

CALL Stars (7)

Question 42

What is a procedure known as in python

how to make one

Answer 42

Void function

define a function but with no return statement

Question 43

How to print without line break in python

Answer 43

print(“*”, end = “”)

Question 44

pseudocode syntax for functions

Answer 44

FUNCTION Celsius (Temperature : REAL) RETURNS REAL
RETURN (Temperature – 32) / 1.8
ENDFUNCTION

Question 45

How to call a function in pseudocode

Answer 45

Must be assigned to a variable since it always returns a value

eg

MyTemp ← Celsius(MyTemp)

Question 46

How to write a non-void function (a fruitful function) in python

Answer 46

Just use a return statement

Question 47

3 components of defining a function in pseudo

Answer 47

» the name of the procedure or function
» any parameters passed to the procedure or function, and their data type
» the data type of the return value for a function.

Question 48

Define a global variable

define a local variable

Answer 48

global variable - can be used by any part of a program. its scope covers the whole program.

local variable - can only be used by the part of the program it has been
declared in. Its scope is restricted to that part of the program.

Question 49

4 library routines and their purpose

Answer 49

» MOD – returns remainder of a division

» DIV – returns the quotient (i.e. the whole number part) of a division

» ROUND – returns a value rounded to a given number of decimal places

» RANDOM – returns a random number

Question 50

How to use each library routine in pseudocode

Answer 50

Value1 ← MOD(10,3)

Value2 ← DIV(10,3)

Value3 ← ROUND(6.97354, 2) returns the value rounded to 2 decimal places

Value4 ← RANDOM()
returns a random number between 0 and 1 inclusive

Question 51

How to use library routines in python

Answer 51

% - mod operator
// - floor division
round(6.97354, 2) {rounds to 2 dp}

import random
random.randint(3, 9)

Question 52

What is divmod in python

Answer 52

divmod(x,y) provides both answers where the first answer is DIV and the second answer is MOD

Question 53

How to comment in
python
pseudo

Answer 53

#

psuedo - //