collections-utilities-and-dates

week 14

This week we will review collections, and talk about various topics in Chapter 15.

Related youtube video playlist

Agenda

• Homework questions
• Homework comments
• comparing floating point numbers is hard
• Integers do division with truncation in Java, FP are the correct thing to use for division.
• How to remove punctuation? RegEx of course: .replaceAll(",|!|\\.|\"", "")
• Topic: Arrays util
• In class work: create an array, sort it, then do binary search on it.

Example of an FP rounding error.

> 0.3 === 0.2 + 0.1
false

// How do you deal with this?
// you use an error factor:
> 0.3 - (0.2 + 0.1) < 0.00000000001
true

Topics (new content)

• copying an array
• comparing arrays
• sorting arrays (Comparable interface, and comparator classes)
• binarySearch on array.
• Date objects
• Calendar objects
• Regex (Matcher and mather.find())