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Questions tagged [function-calls]

Function (or method) calling is the act of using a function or a method.

Functions (or methods) are blocks of code.
They are there, ready to perform some action (a sequence of instructions, including the possibility of calling other functions - even themselves, which is called recursion).
If nobody calls them, the are useless (dead code).

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Implicit declaration of function "..." is invalid in C99?

I'm trying to declare a function within another function. So here's part of my code: ViewController.m - (void)updatedisplay{ [_displayText setText:[NSString stringWithFormat:@"%d", counter]]; } - (IBAction)minus1:(id)sender { counter--; …
Rouvis
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Difference between ISR and Function Call?

I want to understand difference between ISR (Interrupt Service Routine) and Function call. I feel both the function call and ISR are the same from the hardware perspective. Please Correct me if I am wrong. All I could found about ISR and Function…
Nilesh Agrawal
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how do procedure calls work in assembler?

I just started tinkering with ASM and I'm not sure if my understanding of procedure calls is correct. say at some point in the code there is a procedure call call dword ptr[123] and the procedure consists of only one command, ret: ret 0004 what…
int3
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Passing Function name as arguments to a function

Is it possible to pass the name of a function(say A) as an argument to another function (say B), and then call function A from function B. That is the function name will be stored in a variable in B, and using it call the function whose name is in…
Balanivash
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Confusion around function call resolution

This question is inspired by this one. Consider the code: namespace ns { template void swap(T& a, T& b) { using namespace std; swap(a, b); } } After some test with GCC, I found that swap(a, b); resolves to 1) std::swap if…
Lingxi
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IE operating faster with function calls?

Looking for ways to optomize my code, I happened upon this jsPerf test. Not expecting anything other than to have my notion of the slowness of function calls reaffirmed, my results with IE 9 really threw me for a loop. Code which utilized function…
Trey Keown
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arguments are reversed for a C function

I have a function that multiply two matrices A and B then prints the result. I got two different outputs when running the program in two similar ways. first: FILE *f; f = fopen("in.txt","r"); struct Mat* A = read_mat(f); struct Mat*…
M.ElSaka
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PHP: call_user_func_array: pass by reference issue

The below function generates error when a function contains referenced arguments eg: function test(&$arg, &$arg2) { // some code } Now I can not use call_user_func_array for above function, it will generate an error. How to solve this problem? I…
Sarfraz
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Doxygen to document all functions in a class with call graph?

What would be the best way to figure out all the calls made in a C++ class? I would like to not only find all the calls, I want to find out functions that aren't being called at all so I could clean up my code. I have heard that doxygen can work…
user1496542
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performance implications of global variables in c

I have 5 functions which gets called 10000+ times (on an average). All of them modifies/uses certain variables. I know it is bad practice to have global variables. But for performance sake, does it make sense to keep them global and not pass them…
hari
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C - Output explanation of printf("%d %d\n",k=1,k=3);

How to explain the output of the below code: include int main(void) { int k; printf("%d %d\n",k=1,k=3); return 0; } Ideone Link My thinking was that 1 will be assigned to k variable and then 1 would be printed. Similarly 3…
jayd
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`this` keyword equivalent in delphi

Let's say that we have this class: unit Traitement; interface type TTraitement =class public function func1(param:String): String; function func2(param:String): String; end; implementation function…
Billydan
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Does over-using function calls affect performance? Specifically in Fortran

I habitually write code with lots of functions, I find it makes it clearer. But now I'm writing some code in Fortran which needs to be very efficient, and I'm wondering whether over-using functions will slow it down, or whether the compiler will…
Samizdis
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how rsp is decremented in prologue on a X86-64 architecture

I am trying to understand how functions are called in C. When I disassemble this code (gcc - gdb; I am on Linux with an i5-3320M) to get the prologue of function toto: void nop(){return ;} void toto(int i, int j) { return; } int main(int argc,…
GerardBouchar
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Call a function by an external application without opening a new instance of Matlab

Is there a way to call Matlab functions from outside, in particular by the Windows cmd (but also the Linux terminal, LUA-scripts, etc...), WITHOUT opening a new instance of Matlab each time? for example in cmd: matlab -sd myCurrentDirectory -r…
Robert Seifert
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