3_2_11 Structured Programming

You should be able to:

Describe the structured approach to programming.
Explain the advantages of the structured approach.

REVISE:

What is structured programming?

Structured programming refers to creating blocks of code made up of:

Subroutines
If/else statements
Loops

What are the advantages of the structured approach?

Advantages are:

It can improve the quality of the code because it is structured in blocks and each block is tested independently
Decisions can be made through branching (if statements, while loops)
It stops the need for GOTO statements that can lead to confusing code
It can improve the clarity of the code because subroutines make it easier to see clearly what is happening at each stage
It can reduce development time through faster error handling and the ability to work with other programmers
It makes it easier to find and fix errors because they are isolated in subroutines

TEST:

Download and print the test paper here: https://drive.google.com/open?id=0B5fLtQ0Xgr2PSTZTSWRaVWZMZ1k
Try the mock test yourself.
Use the 3.2.11 Walking Talking Mock below to guide you through answering the questions.

Programming Task

Topic 2 Programming Challenge 1.pdf

The two text files can be download here:

A Possible Solution (TRY IT FIRST BEFORE LOOKING HERE!)

The video below shows my attempt at the solution. If you decide to watch the video then look out for:

How I error check
How many mistakes I make before I get it right
How I used resources from other programs (snippets from computingtextbook) to help me remember some of the syntax
How I structured the solution
How I used meaningful identifiers

This solution isn't perfect and another hour or two of coding would make it an efficient solution.

A good programmer would have...

More annotations
Accompanying documentation
A more efficient "enterReg()" subroutine
The option to go back to the main menu after checking the authentication

The Python Code from the Video:

def enterReg(): #user enters the registration

    lengthCheck = ""

    first2Letters = ""

    first2region = ""

    fthLetterspace = ""

    second2year = ""

    lastThree = ""

    print ("Enter a registration number to authenticate")

    registration=input().upper()

    print ("You entered..."+registration)

    print ("Is this correct? Y / N")

    answer = input().upper()

    while answer not in ["Y","N"]:

        print ("You must enter Y or N")

        answer = input()

    if answer == "Y":

        trueCount=0

        print ("Registration Entered")

        print ("Authentication started")

        lengthCheck=(checkLength(registration,lengthCheck))

        if lengthCheck==True:

            trueCount+=1

        print ("Registration Correct Length: "+str(lengthCheck))

        first2Letters=(f2Letters(registration,first2Letters))

        if first2Letters==True:

            trueCount+=1

        print ("First two characters are letters: "+str(first2Letters))

        first2region=(f2Region(registration,first2region))

        if first2region==True:

            trueCount+=1

        print ("The region is valid: "+str(first2region))

        second2year=(s2Year(registration,second2year))

        if second2year==True:

            trueCount+=1

        print ("The year is valid: "+str(second2year))

        fthLetterspace=(fthSpace(registration,fthLetterspace))

        if fthLetterspace==True:

            trueCount+=1

        print ("The 5th Letter is a Space: "+str(fthLetterspace))

        lastThree=(lstThree(registration,lastThree))

        if lastThree==True:

            trueCount+=1

        print ("The last three characters are letters: "+str(lastThree))

        if trueCount==6:

            print ("Registration Number is Authentic")

        else:

            print ("Registration Number is Fake")

    else:

        enterReg()

def quitApp(): #quits the program

    print ("Are you sure you want to quit? Y / N")

    answer=input().upper()

    while answer not in ["Y","N"]:

        print ("You must type Y or N")

        answer=input().upper()

    if answer=="Y":

        quit()

    else:

        menu()

def checkLength(registration,lengthCheck): #checks if the reg is the length is 8 characters

    regLength = (len(registration))

    if regLength!=8:

        lengthCheck=False

    else:

        lengthCheck=True

    return lengthCheck

def f2Letters(registration,first2Letters): #checks the first two are letters

    checkLetters=[]

    firstTwo=(registration[0:2])

    for letter in firstTwo:

        alphabet=letter.isalpha()

        checkLetters.append(alphabet)

    if checkLetters[0]==True and checkLetters[1]==True:

        first2Letters = True

    else:

        first2Letters = False

    return first2Letters

def f2Region(registration,first2region): #checks the first two are in a valid region

    firstTwo=(registration[0:2])

    f = open('validregion.txt', 'r')

    first2region = False

    for line in f:

        lineFirstTwo=line[0:2]

        if lineFirstTwo==firstTwo:

            first2region=True

    return first2region

def s2Year(registration,second2year): #checks if the second two are a valid year

    secondTwo=str(registration[2:4])

    f = open('validyear.txt', 'r')

    second2year = False

    for line in f:

        lineSecondTwo=str(line[0:2])

        if lineSecondTwo==secondTwo:

            second2year=True

    return second2year

def fthSpace(registration,fthLetterspace): #checks if the fifth letter is a space

    fthLetter=(registration[4])

    if fthLetter == " ":

        fthLetterspace=True

    else:

        fthLetterspace=False

    return fthLetterspace

def lstThree(registration,lastThree): #checks if the last three are letters

    three = registration[5:8]

    letterCount=0

    for letter in three:

        if letter.isalpha():

            letterCount+=1

    if letterCount == 3:

        lastThree=True

    else:

        lastThree=False

    return lastThree

def menu(): #menu system

    print ("Welcome to the License Authentication Application")

    print ("-------------------------------------------------")

    print ("Choose an option:")

    print ("1. Enter a Registration")

    print ("2. Quit")

    print ("Enter an option number...")

    option=input()

    while option not in ["1","2"]:

        print ("Enter either 1 or 2")

        option=input()

    if option=="1":

        enterReg()

    elif option=="2":

        quitApp()

menu()

SOURCE RECOGNITION - PLEASE NOTE: The examination examples used in these walking talking mocks are samples from AQA from their non-confidential section of the public site. They also contain questions designed by TeachIT for AQA as part of the publicly available lesson materials.