Class 10: Binary Representation of Integers

Held: Tuesday, February 7, 2006

Summary: Today we investigate the binary representation of integers.

Related Pages:

• EBoard.
• Espresso: Representing Integers in Binary.
• Espresso: Lab on Representing Integers in Binary.
• Javadoc for java.lang.Integer.

Notes:

• Remember: No programming homework for Wednesday.
• I have significantly rearranged the schedule of topics for the first five weeks.
• I don't expect you to be able to read the Sun Javadoc in depth. Rather, I expect you to be able to scan it for methods that might be useful. I also want you to be used to looking at it for help or ideas.

Overview:

• Remaining issues from numbers.
• Basics of binary representation.
• Lab.

Numbers Lab, Concluded

• Are there any remaining questions or observations from the lab on numbers in Java?
• Finish that lab if you have not done so.

Basics of Binary Representation

• Everything is represented as a series of 0's or 1's.
• For non-negative integers, easy technique: base-2.
• For integers that can be negative or positive, use two's complement: To negate, flip bits and add 1.
• Questions?

Lab on Binary

• Do the lab.
• Be prepared to reflect.