After
a long time, I'm writing this post, actually one of mine friend asked a
question to me that, why c language compiler gives an error while compiling a
program having use of modulus operator with float (real) type values. So

from there I thought about writing this post.

from there I thought about writing this post.

Firstly
I should tell you the use of modulus operator (%) in programming languages.
Each programming language has same usage of modulus operator and in C++ this
operator is also called as remainder operator.

Modulus
Operator (%) is a binary operator that’s why used with two operands. This
operator works similar like division operator but division operator gives
quotient and in Modulus operator the output is remainder after dividing two
operands on which modulus operator is applied.

**Example**: -

After
seeing example you have found that modulus operator gives remainder of operands
after division of them. But this example shows use of modulus operator with
integer type values.

When
we use float or real type values with this modulus operator compiler will gives
error like this.

In
this image you will find that compiler says this modulus operator (%) is invalid
for this type values i.e. float type values.

**The question arises here why float type values are not allowed for modulus operator in c & c++.**

For
this you should remind the basics of mathematics and programming. When we use
integer type values and divide them we will get or return quotient of division
by (/) division operator and the remainder value is discarded by operator
because the work of division operator is to give quotient from division
operation.

Similarly,
when we use modulus operator (%) we know the output should be the remainder and
if we use integer value modulus operator will do division operation and the
remainder value will gives as output (as like in division operation this
remainder value is discarded by division operator),

**but in the case of floating type values for operands in modulus operator when division operation is applied by modulus operator the remainder doesn’t comes out because for floating type values division operation floating (decimal) values comes out (such as: 1.4, 2.344, etc.) and remainder value will always be void for floating type values with modulus operator.**

And,
that’s why at the time of C99 version another function is given by makers for
modulus operation with floating type values i.e.

**fmod()**which is used in C & C++ when float or real type values are used for modulus operations.
This

**fmod()**function used hybrid approach to solve this issue i.e. internally rounding off the real type operands to integer type quotients and finally gives remainder of floating type values in C & C++.**If you found any mistakes or have suggestions and new info please let me know in comments below.**

## 4 comments

Sir if we divide 3.0 and 7, then it will never completely gives remainder 0 ......So explain me about these type of cases..

ReplyDeleteIf we divide 3.0 by 7 then you'll see it's not dividing so it'll always give you the term as answer(remainder).

DeleteSir if we divide 3.0 and 7, then it will never completely gives remainder 0 ......So explain me about these type of cases..

ReplyDeleteSir can you give a example by the use of fmod()

ReplyDeleteIf you have any questions or suggestions, you are free to ask, i will appreciate that and, i will try my best...