Flowchart - TDSB School Web Site List
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Transcript Flowchart - TDSB School Web Site List
PROBLEM SOLVING
Developing a Program
Flow Charts
TEE/TIK 20
Writing a program
Defining the problem
Planning
Coding, including errors correction, testing
Documenting
Write down the steps, draw a flowchart
Programming
Write down what the program will do
Adding comments
Implementing
Improvement, making the program better
Objective
A program
can be divided into 3 parts:
Input
data
Processing data – Calculation, etc.
Output information/results
Input
Calculation/
Processing
Output
Planning - Flowchart
A Diagram that uses special symbols
showing the steps of a program
What is a flowchart?
A diagram
made up of symbols of
various shapes connected by arrows.
Those symbols indicate either actions to
be taken or decisions to be made.
It may be used to describe any
complicated process when a mixture of
actions & decisions take place
It helps us planning & programming.
Flowchart Symbols
Decision symbol
T (Selection, Conditional
Statement)
Terminal symbol
(Start & Stop)
Processing symbol
(Calculate, Assign,
Initialize, Declare)
F
2
1
A
Input/Output symbol
(get, put)
A
Page connector
(used when run out of
room at the bottom)
Step connector
(go from one part to
another)
Terminal Symbol
start
stop
Only one “start” & one
“stop”
1 arrow only
Each flowchart starts
with one “start” & ends
with one “stop”
Input / Output Symbol
2 arrows only
Input Data
1 in & 1 out
get fullname:*
Display result
put fullname
Processing Symbol
2 arrows only
Declaration
var sum : real
Initialization
1 in & 1 out
sum := 30.14
Calculation
Decision Symbol
3 arrows
Q. ?
F
T
Question
1 in & 2 out
worded this way that
the answer is Yes or
No
2 out going arrows
T (True, Yes)
F (False, No)
Page connector
2
1
1 arrow only
Shows the next page
Shows the previous page
Run out of space
Step connector
1 arrow only
Appear in
A
A
1 to 1
Many to 1
Use letters
Go from one step to
another
Arrows
From Top to Bottom
& from Left to Right
Make turn
Join together
Example
start
bell
ringing
phone?
Y
answer the
phone
N
door?
Y
see who is
at the door
1.is it the door bell?
2.start
3.answer the phone
4.turn off the alarm
5.is it the telephone?
N turn off the 6.listen to bell ringing
7.stop
alarm
8.see who is at the door
stop
start
Example (Turing)%=comment
Define PI
% the symbol **3 =cub
const PI := 3.14
var radius, volume : real
put “please enter...”..
get radius
volume := (4/3)*PI*radius**3
put “”
put “The volume is”, volume %
Declare
radius, volume
ask radius
input radius
Calculate
volume
output
volume
stop
Example
start
1.start declare variables
2.what is the mark
3.ask for mark
4.check mark>=50
5.>=50 show “U Pass”
6.<50 show “U Fail”
7.stop
var mark: real
ask mark
get mark
_____
mark>=50
F
“U Fail”
A
stop
T
“U Pass”
A
Example with Trace Table
Trace Table
start
Declare & Initialise
x & y to1
A
sum of x&y
is
sum<20
N
Show x,y
and sum
stop
Y
x=y
y = sum
A
x
y
sum
1
1
2
1
2
3
2
3
5
3
5
8
5
8
13
8 13
21
Programming
Convert
the steps to instructions /
programming languages
Debug – correct the errors
Syntax
errors
Grammar mistakes which are easily found out
Logical
errors
Programs run & work but the outcome is not
correct / expected
Can be found by testing
Documentation
Add
comments
Easier
Use
to understand
spaces wisely
Blanks,
Tabs, New Lines
Easy to trace, follow & understand
Choose
Easy
variables & constants names
to understand, not too long or short
Implementation
Ask others to run your program
Make it more user friendly including
input & output
Make it more efficient (fewer lines)
Make it run faster
Add ending screen etc.
Good Luck!