an easy c question [duplicate] - c

This question already has answers here:
Closed 11 years ago.
Possible Duplicates:
What belongs in an educational tool to demonstrate the unwarranted assumptions people make in C/C++?
In C99, is f()+g() undefined or merely unspecified?
In the statement, "function1() + function2(); "which function will be called first?

The order of evaluation is unspecified.
Read this answer.

Related

fortran function to find available file unit [duplicate]

This question already has answers here:
getting free unit number in fortran
(2 answers)
Closed 7 years ago.
I can write a FORTRAN function to find an available file unit, but I was certain there was already an intrinsic. But if there is, I can't find anything about it. Is there such a thing or am I dreaming?
UPDATE: Apologies for the duplicate. Did a search, but it didn't show up.
I guess, you are looking for newunit (available with F2008, shown at the bottom of that link in the Fortran Wiki).
Ups, has already been answered.
maybe you were thinking of inquire?

What does `register` do in GStreamer [duplicate]

This question already has answers here:
"register" keyword in C?
(19 answers)
Closed 8 years ago.
I was reading some gstreamer code and fell on this line
register int i;
Does anyone know what the register keyword does ?
Another SO question has already answered this.
Answer From Brian Knoblauch:
It's a hint to the compiler that the variable will be heavily used and
that you recommend it be kept in a processor register if possible.
Most modern compilers do that automatically, and are better at picking
them than us humans. :-)
So, essentially, it assures the programmer that the compiler will know that the variable will be utilized numerous times and to keep that variable in the CPU register. As stated in the other answer, most compilers do this automatically.

How is the function "sin" realized? [duplicate]

This question already has answers here:
How does C compute sin() and other math functions?
(22 answers)
Closed 9 years ago.
Anybody can explain or show how is the function "sin" (or "sinf", "sinl") realized in C.
Intuition suggests that it should be somewhere in the math.h but I did not see anything there
There's a couple ways I can think of right off the bat:
Lookup tables
Approximation via Taylor series (which can be easily made accurate to a number of significant digits).

Concept of function pointers in C? [duplicate]

This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
What is the point of function pointers?
hi all,
I want to get the basic and concrete idea of function pointers in C language.
ie 1) its usage in C
2) main applications it is currently using
3) unique features
4) its scope in embedded applciations etc
Hoping your co operation in this too.
__Kanu
Function Pointers are pointers, that is variables, which point to the address of a function.
Nice example here. Also this answer is a must read.

why global variable in C takes zero as initial value? [duplicate]

This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
Static variable initialization?
why global variable in C takes zero as initial value?
This required for a compiler to conform to the C standard.
The reason for the design choice is likely that having random garbage in your uninitialized variables makes errors much harder to detect.

Resources