Why am I getting a 'called object 0 is not a function error'?

Question

I\'m a C# developer trying to learn C (followed by C++). I am going native, working on Ubuntu using vim as my text editor, and the Gnu C Compiler (gcc) to compile.

I\'m

Answer 1

As people have pointed out

int celcius = (5/9)(i-32);

Should be

int celcius = (5/9)*(i-32);

However the reason you are getting that particular error message is that

int celcius = (5/9)(i-32);

is being evaluated at run time as

int celcius = (0)(i-32);

And the runtime system sees (0) as a pointer.

So you need to change your math to avoid the integer division

Answer 2

This line is problematic:

int celcius = (5/9)(i-32);

because the compiler thinks you're trying to invoke a function specified by (5/9). If you wished to do a multiplication, you should do:

int celcius = (5/9)*(i-32);

instead.

Moreover, if you expect floating-point values to be returned from that calculation, you should do:

int celcius = (5.0/9.0)*(i-32.0);

because 5/9 is an integer division and will never return a floating-point value.

Answer 3

In C (and I am assuming that in other languages too :)) an arithmetic operator is needed to perform an arithmetic operation.
Change

int celcius = (5/9)(i-32);

to

int celcius = (5/9)*(i-32);

Answer 4

change

int celcius = (5/9)(i-32)

to

 int celcius = (5/9)*(i-32);