This week's book giveaways are in the Refactoring and Agile forums.We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line!See this thread and this one for details.
Win a copy of Re-engineering Legacy Software this week in the Refactoring forum
or Docker in Action in the Cloud/Virtualization forum!

# Using Modulus

John Daniels
Greenhorn
Posts: 4
When using the modulus, if a<b, then a%b = a. But why, if a is negative, does -a%b = -a? According to the division algorithm, the remainder r must be >= 0 and <|b|.

Edwin Dalorzo
Ranch Hand
Posts: 961
The formula Java use for integral modulo operations is

Let's see some examples:

Case 1: Positive Numbers -> 7 % 2

Conclusion: Positive yield possitive

Case 2: Negative Divisor -> 7 % -2

Conclusion: Negative divisor yields positive results.

Case 3: Negative dividend -> -7 % 2

Conclusion: Negative dividend yields negative results

Case 4: Negative dividend and divisor -> -7 % -2

Conclusion: Only negative dividend affect the result
[ May 09, 2006: Message edited by: Edwin Dalorzo ]

John Daniels
Greenhorn
Posts: 4
Thanks