1. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
SE1011 Week 4, Class 2
Today
Muddiest Points
Finishing GUI loop example
Nested Loops
Next Half-Exam: Week 5, Monday
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder

2. do-while & nested loops
SE1011
5/21/2019
Muddiest Loop Points
I get the whole concept of loops, but not the application of it
writing loops
What is the difference betwen "while" and "do while"
types of loops
It sounds like some of the class could use another detailed run-through of nested for loops.
nested loops
how to get a nested loop to start another line.
how to make a loop print out a different value and count stars.
for loop notation (semicolon instead of comma)
loop syntax
do while loops and nested loops
do-while & nested loops
Dr. Josiah Yoder

3. Muddiest Loop Points Is there an optimal loop? types of loops
SE1011
5/21/2019
Muddiest Loop Points
Is there an optimal loop?
types of loops
you can exit for and come back, but how can you exit if and come back?
can if loop
How to determine which loop to put first (width or height).
nested loops
Making the programs impossible to break
error handling
nested loops (2x)
going from loop to loop (variables, scanners, etc.)
loop scope?
when to use for versus while?
how nested loops interact (still fuzzy on the star example)
Dr. Josiah Yoder

4. Types of Loops: do-while vs while
Condition checked first
May not enter body
If condition false first time
Body executed first
Will enter body at least once
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder

5. Types of Loops: for vs. while
general-purpose loop
Use when you don't know how many times loop will execute
counting loop
Use when you know how many times loop will execute
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder

6. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
Why loop at all?
To let the computer count
To play video or music
To recover from user errors
To let user repeat a task
To search
…any time you want to run part of your code more than once!
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder

7. Nested Loops – an example
do print "Times to sing? 0 to exit" input timesToSing timesSung 0 while timesSung < timesToSing print count timesSungtimesSung+1 while times > 0
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder

8. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Nested Loop Design
The outer loop is the main task
The inner loop performs one step of that task
You can test the inner loop without the outer loop
Just supply variables
The outer loop can change the variables that the inner loop sees
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder

9. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
Coding practice
See slides from last time, and …
Today:
CodingBat: starOut
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder

10. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
Nested Loops
Design a program to print out a rectangle of '*' characters with width characters per line and height lines of characters (pseudocode or flowcharts)
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder

11. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder

12. SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
5/21/2019
Acknowledgement
This course is based on the text
Introduction to Programming with Java by Dean & Dean, 2nd Edition
SE-1011 Slide design: Dr. Mark L. Hornick Instructor: Dr. Yoder
Dr. Josiah Yoder