Can you please tell me how much is (-2) % 5 ?
According to my python interpreter is 3, but do you have a wise explanation for this ?
I've read that in some languages the result can be machine-dependent, but I'm not sure though.
Thanks for your help.
...

I read somewhere once that the modulus operator is inefficient on small embedded devices such as 8 bit micros without integer division operator. Perhaps someone can confirm this but I thought the difference is 5-10 time slower than with an integer division operation.
Is there another way to do this other than keeping a counter variable ...

So, lets say I have a number 123456. 123456 % 97 = 72. How can I determine what two digits need to be added to the end of 123456 such that the new number % 97 = 1? Note--it must always be two digits.
For example, 12345676 % 97 = 1. In this case, I need to add the digits "76" to the end of the number.
(This is for IBAN number calcul...

I need to do a modulus operation on very large integers. The biggest integer supported by my platform (edit: .NET 2.0) is a 64 bit integer, which aren't big enough for the numbers I'm working with.
How can I do a modulus on really big integers, like 12654875632126424875387321657498462167853687516876876?
I have a solution that treats t...

I'm talking about this:
If we have the letter 'A' which is 77 in decimal and 4D in Hex.
I am looking for the fastest way to get D.
I thought about two ways:
Given x is a byte.
x << 4; x >> 4
x %= 16
Any other ways? Which one is faster?
Thanks.
...

I'm brand new to Erlang. How do you do modulo (get the remainder of a division)? It's % in most C-like languages, but that designates a comment in Erlang.
Several people answered with rem, which in most cases is fine. But I'm revisiting this because now I need to use negative numbers and rem gives you the remainder of a division, which ...

Perl
print 2 % -18;
-->
-16
Tcl
puts [expr {2 % -18}]
-->
-16
but VBScript
wscript.echo 2 mod -18
-->
2
Why the difference?
...

In JavaScript the % operator seems to behave in a very weird manner. I tried the following:
>>> (0 - 11) % 12
-11
Why does it return -11 instead of 1 (as in Python)?
I am sure I am doing or expecting something wrong, but the docs don't tell me what.
...

I have a class which represents a shape. The Shape class has a property called Angle. I want the setter for this property to automatically wrap the value into the range [0,359].
Unfortunately, a simple _Angle = value % 360; only works for positive numbers. In C#, -40 % 360 == -40. Google calc does it the way I want it. The value should ...

In Perl, the % operator seems to assume integers. For instance:
sub foo {
my $n1 = shift;
my $n2 = shift;
print "perl's mod=" . $n1 % $n2, "\n";
my $res = $n1 / $n2;
my $t = int($res);
print "my div=$t", "\n";
$res = $res - $t;
$res = $res * $n2;
print "my mod=" . $res . "\n\n";
}
foo( 3044.952963...

The python 2.6 docs state that x % y is defined as the remainder of x / y (http://docs.python.org/library/stdtypes.html#numeric-types-int-float-long-complex). I am not clear on what is really occurring though, as:
for i in range(2, 11):
print 1.0 % i
prints "1.0" ten times, rather than "0.5, 0.333333, 0.25" etc. as I expected (1/2...

I need to calculate the modulus of a number in XPath, but this won't work:
<xsl:if test="(count()%8)">
How would I do it? Looked at the XPath function reference here, but didn't see anything like that.
THANKS FOR THE PROMPT ANSWERS!
...

I'm trying use the modulo operator (%) on long longs, and it seems to return 0 if the number is above the range of an unsigned int. Is there an operator or function that I should be using instead, or should I roll my own?
-- Update: sorry for the lack of example code before, I was in a hurry, heading out the door --
Here's the code:
l...

I need to calculate modulus with large number like :
<?php
$largenum = 95635000009453274121700;
echo $largenum % 97;
?>
It's not working... beacause $largenum is too big for an int in PHP.
Any idea how to do this ?
...

In 32 bit integer math, basic math operations of add and multiply are computed implicitly mod 2^32, meaning your results will be the lowest order bits of the add or multiply.
If you want to compute the result with a different modulus, you certainly could use any number of BigInt classes in different languages. And for values a,b,c < 2^3...

In Python and Ruby, signed integer division truncates towards negative infinity, and signed integer modulus has the same sign the second operand:
>>> (-41) / 3
-14
>>> (-41) % 3
1
However, in C and Java, signed integer division truncates towards 0, and signed integer modulus has the same sign as the first operand:
printf("%d\n", (-41...

Write code to determine if a number is divisible by 3. The input to the function is a single bit, 0 or 1, and the output should be 1 if the number received so far is the binary representation of a number divisible by 3, otherwise zero.
Examples:
input "0": (0) output 1
inputs "1,0,0": (4) output 0
inputs "1,1,0,0": (6) out...

Hi!
I try to calculate with JS' modulo function, but don't get the right result (which should be 1). Here is a hardcoded piece of code.
var checkSum = 210501700012345678131468;
alert(checkSum % 97);
Result: 66
Whats the problem here?
Regards,
Benedikt
...

I have to implement a digital envelope using AES and RSA, but I am having problems with the .NET implementation of the RSA algorithm.
I have managed to encrypt the data (AES) with the random symetric key, but now I have to encrypt the key with RSA.
The key is an array of bytes (byte[]) and the public key I have tells me only the modulu...

How do I handle big integers in C#?
I have a function that will give me the product of divisors:
private static int GetDivisorProduct(int N, int product)
{
for (int i = 1; i < N; i++)
{
if (N % i == 0)
{
Console.WriteLine(i.ToString());
product *= i;
...