abs of float

how can we find the absolute of a float variable since it gives warning of data loss?

Quote:

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Originally posted by vVv

Code:

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#include <cmath>
...
float foobar = -1.23;
foobar = std::abs( foobar );

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Is abs() a member of std, I think it's not?

And does any body know why does the compiler give that warning?

If you include cmath, the abs function is in the std namespace. I don't see anything wrong with it.

I asked about this because when I compiled the following code( using MS VC++ 6:

Code:

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#include <cmath>

int main()
{

        float foobar = -1.23;
        foobar = std::abs( foobar );
        return 0;
}

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I got the following errors and warnings:

Quote:

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--------------------Configuration: Cpp2 - Win32 Debug--------------------
Compiling...
Cpp2.cpp
C:\Documents and Settings\Ammar\My Documents\C++\Cpp2.cpp(6) : warning C4305: 'initializing' : truncation from 'const double' to 'float'
C:\Documents and Settings\Ammar\My Documents\C++\Cpp2.cpp(7) : error C2653: 'std' : is not a class or namespace name
C:\Documents and Settings\Ammar\My Documents\C++\Cpp2.cpp(7) : warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data
C:\Documents and Settings\Ammar\My Documents\C++\Cpp2.cpp(7) : warning C4244: '=' : conversion from 'int' to 'float', possible loss of data
Error executing cl.exe.

Cpp2.exe - 1 error(s), 3 warning(s)

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Thanks in advance...

>using MS VC++ 6
That's your problem, VC++ 6 doesn't conform to the latest standard properly.

-Prelude

Thanks alot, vVv and Prelude...
Now it's clear...

The abs( ) function takes an integer number and returns an integer value. You want to use the function fabs( ) which takes a double and returns a double.

Alternatively you can use fabs() defined in math.h, which has been created specifically for floating point arguements.