Absolute value without sign *Resolved*

Is there a way in C++ to get the absolute value of an integer ??


if after a calculation i get a value returned -2 how can i use some function to get 2

I don't want to write

PHP Code:

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if(c<0) c = c -c -c ; 


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abs(value)

Don't know if there are any float/double etc methods for this - probably, but abs is the right one for ints.

Need math.h I think for this.

HD

In C++, it's the <cmath> header :)

You can use fabs() for floating-point numbers.

Thank should have tried it first.

There are a lot of 'abs' functions - cabs(), labs(), etc.

The generally accepted dogma is that you should use a macro for functions like sgn(), abs(), etc because they are faster - a lot faster.

Kinda like this:

Code:

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#define abs(c)  ( (c<0) ? (-1)*c : c )

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You can also force 'inlining' by using macros -
This does a complex reciprocal for instance.
arg & out are type Complex (a struct)

Code:

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#define LCMPLXrecip(arg,out)        \
{ long denom; denom = lsqr((arg).x) + lsqr((arg).y);\
if(denom==0L) overflow=1; else {(out).x = divide((arg).x,denom,bitshift);\
(out).y = -divide((arg).y,denom,bitshift);}}

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