CSIS 110 - Lecture 14
Announcements
Quiz – Wednesday, Feb 15. Continue reviewing chapter 4. Homework due Friday.
For/While Loop Relationship
How can you convert one to the other? Let's look at the parts, see how they relate to each
other
What are the ‘rules’ for deciding whether to use a for loop or a while loop?
- For loop: when you know ahead of time how many iterations there are.
- While loop: when you just keep going until some condition is true
Examples: Given a sorted array of ints: int[] myArray;
Use a for or while?
- to display all the values in the array
- to find the first element whose value is larger than 15?
- to display the last 5 elements of the array?
- to calculate the sum of the elements?
- to search for an element with the value 27?
Removing all items from a list
Let's look at some different ways for removing all the items from a list.
Load the student2 project
Note that in this version
Students have a studentID
I have added a buildStudentBody method that creates a bunch of students
There is a printAllStudents method that prints all of the students in the
studentBody
Try to write a method that removes all of the elements in a list. [Copy the
printAllStudents method an modify it to call remove instead – Analyze why this doesn’t
work]
Look at alternative options
1) delete from the rear
2) always delete the front item – discuss why this version doesn’t have an obvious
‘prepare for next iteration’ part of the loop
