PROGRAMMINGIn
Lesson 5
RECAP
Complete the starter activity
OBJECTIVES Understand how to use looping statement (while) Understand to use the break statement Understand the development process of flow charts to
comments to code
OUTCOMES All-Level 4 written code using while - with help
developed programs using pseudo code
Most-Level 5 Be able to write a these with little help.
Some-Level 6 Independently write these and adapt them and complete the extension tasks.
LOOPS
You might remember this code from your truth table of last lesson. It is part of the function that got the user input.
It uses a while statement to keep asking the user to input a value until it is one of the required values.
WHILE STATEMENT
while expression : statement 1 statement 2 statement 3
Statements are executed while the expression is true
Notice the indentation – this defines
the statements that are in the while statement
Don’t forget the full colon
WRITE A LOOPY PROGRAM – PSEUDO CODE
Write a program that asks the user for a number and counts down to 1 displaying each number as it goes.
a=int(a) – converts number a to an integer
You have the rest of the knowledge.
Extension:Get you program to calculate the factorial of the number.
Hint: factorial of 4 is 4 * 3 * 2 * 1.
start
Ask user for a number
Convert to integer
Display number
Subtract one
Is number > 0
Yes
endNo
• Write the pseudo code for the program.
• We will then write the program comments from this pseudo code
• We will then fill in the code for each comment.
end
WRITE A LOOPY PROGRAM - COMMENTS
Is number > 0
start
Ask user for a number
Convert to integer
Display number
Subtract one
Yes
No
WRITE A LOOPY PROGRAM - CODE
Extension:Get you program to calculate the factorial of the number. Hint: factorial of 4 is 4 * 3 * 2 * 1.
With your classmate you have 2 mins to discuss…
What was most difficult in the program
What was most fun
What was the boring part
CLASS DISCUSSION
WHILE STATEMENT BREAK
while expression : statement 1 statement 2
breakThis command quits from the while statement – even
if the expression is still true.
Statements are executed while the expression is true
Notice the indentation – this defines
which statements are in the
while statement
GUESS THE NUMBER – VERSION 2 Remember this – guessing a random number….
I want you to make it even better
Give the user 6 chances to guess the number - use while statement
Let them know if their guess is too high - if statement
Let them know if their guess is too low - if statement
GUESS THE NUMBER – VERSION 2
WHAT DO WE NEED TO CHANGE
Set guesses to zero
Exit from while loop
Add 1 to guesses
User has a guess
No
NoGuess
= numbe
r
Yes
NoGuess
> numbe
r
Tell user too highYes
Tell user too low
Guess <
number
Yes
Guesses > 6No
Yes Exit from while loop
You have previously written most of this program.
All you need to do is write the new section
Set guesses to zero
Exit from while loop
Add 1 to guesses
User has a guess
No
No
Guess =
number
Yes
NoGuess >
number
Tell user too high
Yes
Tell user too low
Guess <
number
Yes
Guesses > 6
No
Yes Exit from while loop
WRITE THE CODE
EXTENSIONS
Make the random number range from 1 to 30
Let them know the random number if they fail to guess it.
PLENARY
Complete the Lesson 5 plenary Quiz