The art of drawing a road mapFlowchartSymbolsOval
(racetrack)Start or Stop (Terminator)RectangleProcess (calculation,
value assignment, etc)Rectangle with double vertical sidesA
predefined processAllows you to represent something complicated at
an early stage and basically show that it goes here in your flow of
activityRhomboid (slanted rectangle)Input / output
(data)DiamondDecisionArrows indicate direction or flow of
activitySmall circle (possibly with letter inside)on page
continuationHome Plateoff page continuationCalculate
AvgAvgGradesPerform Tax CalculationStartGet
TempCentAge>21?AFlowchartDemonstrates a sequence of activities
and decisionsCan be used as a roadmap in writing codeCertain shapes
identify code structuresDecision structuresA condition which
evaluates to True or FalseAsks a question which directs the
continued flow of activityRepetition structures (loops)A return to
a prior point in the flowchartNOTE: this return is based on a
condition being either true or falseWhile the shape asking the
question is a diamond and could be an IF statement, the fact that
one of the branches from the diamond returns to a prior point
indicates that the conditional question asked is part of a LOOP and
not an IFFlowchartForces us to think about what we doWe need to
identify each discrete action (process) or question (decision) in
order to solve the problemFlowcharts can identify that we missed
somethingWe have a process which calculates GROSSPAY, and know that
GROSSPAY requires Hoursworked and HourlyPay as input, but we notice
that prior to the calculation, we never bothered to get HoursWorked
(missing input)Weve calculated a result NETPAY, however never
display it to the user (output of our solution)Flowcharts can
identify a sequencing errorWe display a result prior to calculating
itWe can think about things more abstractlyCalculate GrosspayIf we
know someone worked 10 hours at $15/hour the calculation is 10 x
15NOT abstract enough it only works for that single caseWork
backwards. What does the 10 represent? [ Hoursworked]Use THAT name
to represent any value given ATM Password ValidationThe user gets 3
attempts to provide the valid passwordIf validGo to the process
transaction off-page routineIf its the 3rd failed
attemptStop!DecisionValid diamondRepetition3rd attempt question is
part of the LOOP, and not simply an IFHow you can identify the
difference between which structure to code (IF vs. LOOP)
IF statement / variationsIFblnPass=False If AvgGrade > 65
then blnPass=TRUE
IF ..ELSE..ENDIFIf AvgGrade > 65 thenblnPass=TrueElseblnPass
= FalseEnd If
Filling in symbolsProcessesUse a verb or action wordThink of
each process as its own little IPO (Input-Process-Output)Do you
have all of the required inputs to do the process at that point in
time?If not, maybe you missed a step somewhereDecisionsTrue or
falseComparisonAge>21Counter
