## CIS22A - Notes for Week 5, 10/21-10/24

### Announcements and Reminders

• Assignment 4 is due Monday, 10/21
• Tuesday's online time (7:00-8:15 pm)
• Lab Exercise 5 is due Wednesday, 10/23
• Assignment 5 is due next Monday, 10/28
• Women in Computer Science hosting Netflix speaker  -  Monday, 10/28, 12:00-1:15 pm Conf Room B

### Chapter 5 Loops

#### The while loop

while (condition) statement;

while (condition)
{
block of statements
}

Program 5-3 - Page 238
• condition
• local variables and scope
• break
• Using a while loop to validate user input
• Using a counter in a while loop
Some easy examples
• count to 10
• count from 10 to 20
• count from 10 to 1
• count by 2s
• print a list of squares and square roots
• fibonacci numbers
Progam 5-4 - Page 242

#### The do-while loop

do statement while (condition);

do
{
block of statements
}  while (condition);

Progam 5-7 - Page 248

Example

Roll the dice until ...

#### The for loop

for (initialization ; condition ; statement(s) to be executed at end of loop )          statement;

for (initialization ; condition ; statement(s) to be executed at end of loop )
{
block of statements
}

#### Examples

Program 5-9 - Page 253

Program 5-10 - Page 256

Program 5-12 - Page 262

Sentinels

Program 5-13 - Page 264

Averaging

Program 5-14 - Page 267

• Roll the dice 10 times
• factorial

#### while loop

keep rolling the (two) dice until you roll a hundred points

flush the input buffer

#### do-while loop

keep rolling the (two) dice until you roll a hundred points

read words until quit is entered

#### for loop

The Clock

What is the average of 1000000 rolls of the (two) dice?

How many times do you roll doubles in 1000000 rolls?

What percent of your 1000000 rolls are doubles?

What's the sum of this series:  4/1 - 4/3 + 4/5 - 4/7 + 4/9 - 4/11 ... ?

Videos

while Loops

Simple Program Using a Loop

Sentinel Controlled Program
while

condition

evaluate

block

scope

break

do while loop

for loop

validate user input

counter variable

sentinel