I could use an explanation of MODULUS 2

[javierdlm001]

I have read a few definitions, and seen many examples.
Part of them do make sense, but not completely.
So far the best definition I've seen is this one:

"The remainder operator returns the remainder left over when one operand is divided by a second operand. It always takes the sign of the dividend, not the divisor. It uses a built-in modulo function to produce the result, which is the integer remainder of dividing var1 by var2 — for example — var1 modulo var2"

...returns the remainder left over... (of a division)

What "remainder left over" ?
How can there be such thing on the first place?
Maybe I'm not looking at it from the right angle.

I was hoping someone could offer a different definition/approach.

Thanks in advance guys

 

[MakeItSo]

What do you get if you divide 10 by 3?
=>3 and a remainder of 1.

This works for whole numbers only. If one number is a multiple of the other, the modulo is 0. Example: 8 divided by 2 gives 4. No remainder.
9 divided by 2 gives 4, remainder 1. <= This is your modulo right there.

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[javierdlm001]

Excellent!
This is what I needed!
In another words: Fit the smaller number as many times as possible into the larger, and what's left is the remainder.

However, one of the examples at Mozilla, is this one:

2 % 3 // 2

Based on the what I understood from your example, I would have thought that: (2 fits once into 3, with a left over of 1). But seen the example above I can infer I am not getting it.

 

[MakeItSo]

You need to pay attention to the *order* in which the numbers are presented. In this example it is how often does "3 fit into 2"? => 0 times, the 2 remains.

"Knowledge is power. Information is liberating. Education is the premise of progress, in every society, in every family." (Kofi Annan)
Oppose SOPA, PIPA, ACTA; measures to curb freedom of information under whatever name whatsoever.

 

[javierdlm001]

Now I see!
So, if the right number won't fit into the left one, then the left one remains.

Thank you so much MakeItSo

 

[xwb]

Just be aware that the javascript modulus operator, like many of the programming languages have the 1950's Fortran bug - it gives the incorrect answer on negative numbers.

-10 % 3 should be 2, not -1

 

[javierdlm001]

Mmmm, that's a good one!
Thanks a bunch for that xwb