2.2.3 - Additional programming techniques

Question 1

what does .length or len() do

Answer 1

Returns the length of the string

Question 2

How to convert the whole string to uppercase or lowercase

Answer 2

.upper() and .lower()

Question 3

What is concatenation and how is it done

Answer 3

• Joining two separate strings together
• Done using the “+” symbol

Question 4

What does string[x:i] do

Answer 4

• Returns part of a string
• x represents the starting character
• i represents the end of the string (non-inclusive

Question 5

What do .left(x) or .right(x) do

Answer 5

Returns the leftmost or rightmost character from a string
The number in the brackets shows how many characters to return

Question 6

String commands to convert between ASCII and characters

Answer 6

• ASC()
• CHR()

Question 7

what is a record in a database

Answer 7

Type of data structure that stores all of the data relating to one entity in a database

Question 8

What is a database and why is it used

Answer 8

• A method to store data in an organised way (fixed structure)
• This allows easy finding and retrieval of the data needed
• It also allows multiple data types to be stored in the same record

Question 9

How to recognise attributes and records in a database table

Answer 9

• Records are the rows
• Attributes are the columns

Question 10

The 3 SQL commands in the order you have to use them

Answer 10

• SELECT (fields)
• FROM (database table)
• WHERE (criteria)

Question 11

What does the wildcard * do in SQL

Answer 11

• SELECTs all fields

Question 12

What does the wildcard % do in SQL

USED WITH LIKE

Answer 12

• Finds all records with characters like the example criteria
  E.g. WHERE (criteria) LIKE “S%” finds all records beginning with S

Question 13

What are subprograms and the different types of subprograms

Answer 13

• Small programs within a larger program that performs a specific task to produce structured code
• Procedure - performs a task and when it is done, the program continues where it left off
• Function - performs a task, maniuplates data and returns it back to the main program

Question 14

Advantages of subprograms

Answer 14

• Saves time - can be saved as separate modules and used in other programs
• Small so easy to write, test and debug
• Shorter programs - can be called multiple times and only has to be written once

Question 15

What is a global variable

Answer 15

Has a scope of the whole program. Is declared outside of a subprogram and in python, has to be declared before it is used in a subprogram

Question 16

What is a local variable

Answer 16

A variable that is declared in a subprogram and its use is confined to that subprogram

Question 17

What is an array

Answer 17

A static data structure that stores a number of related data items together in the same memory space (contiguous)

Question 18

Why are arrays used?

Answer 18

• Allows for storage of more than one item of data under one identifier which reduces the need for variables
• This makes the code shorter and therefore easy to debug or test