A function declaration is the process of describing only the return type, argument types, and name of a function. This is required in some programming languages to use functions that were defined at a later point in the code or in another file. Use this tag for questions that pertain to or problems caused by forward declaring functions in languages that support or require doing so.
Questions tagged [function-declaration]
549 questions
-1
votes
1 answer
How can i make a struct keep the value ive assigned through the function?
Basically I am trying to assign a value to a struct through a function,so that the value that I've assigned is the same on main() afterwards.
The struct
struct member{
char name;
int age;
}m1;
void assigntostruct(struct member str,int…
kostis14
- 21
- 3
-1
votes
1 answer
Changing the sign of array values in C
I need to write a function that takes the elements in an array and changes the sign (ex. 3 --> -3 or -3 --> 3). l want use this array (int a[2][3] = { { 55,-44,},{1, -4},{6,11} };) instead of ( int a[] = { 5,6,-4};)
What should I do?
#include…
C baby
- 11
- 1
-1
votes
2 answers
Why does this function without a type still work?
Why am I not getting an error even if I declared a function without a type?
If the return type is accepted as some types by default, is it healthy to write codes like this?
If it already works like this with a compiler feature, then why would we…
noob
- 107
- 6
-1
votes
2 answers
Ensure returned pointer is const, without throwing warnings
My goal is to define a clean API for my library.
One of my function returns a pointer that shall not be modified with pointers arithmetic.
To do so at compile-time, I was planning on using the const keyword in the function prototype.
Here's a naive…
gberth
- 467
- 5
- 13
-1
votes
1 answer
Can declaring a function prototype without parameters create security breaches?
I have heard that calling int main(){...} was bad practice and one should rather call the function with its parameters int main(int argc, char* argv[]){...}, I was wondering if this could be generalized to function declarations in headers.
In some…
Binou
- 124
- 9
-1
votes
3 answers
Can I declare a function in a C source file without declaring it in the header file?
I'm only asking because I have an assignment that includes writing a function to find the inverse of a matrix. I did this using Cramer's rule and a determinant function which I added to my header file.
When I submit, however, it uses the header…
Jon D.
- 27
- 2
-1
votes
1 answer
Why doesn't it work if I declare the function like this?
I declared the 'GuGuDan' fn in the first place before main fn, but it showed the error message 'Implicit declaration of function 'GuGudan' is invalid in C99' and didn't work.
so I tried to find another solution and figured it out it works if I…
-1
votes
1 answer
Perl Subroutine Declaration Unexpected Symbols
I have been looking at some Perl code that has some subroutine declarations that make no sense to me. They appear as:
foo($$$$;$);
foo(\$\$\$);
What do the symbols ";" and "\" do or mean in these declarations?
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votes
1 answer
Are all functions inside of an IIFE expressions?
If (function foo(){}) is an expression due to the 'context' as "(Parenthesis)" are a grouping operator and grouping operator can only contain an expression.
Which leads to the question, can you declare a function inside of an IIFE or it would still…
Aleksei Maide
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- 1
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votes
2 answers
Swap 2 values of a stack does not work
#include
#include
using namespace std;
#define NMAX 10 // pre-processing directive
template
class Stack {
public:
T Smain, Saux;
T stackArray[NMAX];
int topLevel;
int getTopLevel()
{
return…
-1
votes
1 answer
Struct as Output of a Function
I wrote this code but when try to compile it, it returns thid error:
:24:8: error: conflicting types for ‘safe_syscall’
:19:10: note: previous implicit declaration of ‘safe_syscall’ was here
I specified the number of lines.
typedef struct syscall…
Peggy
- 639
- 9
- 28
-2
votes
1 answer
how to suppress warnings that C/C++ functions hava no parameters in vscode with clangd?
description
I try to use vscode and clangd to write C/C++, but for those functions whose parameters are empty, vscode will give "A function declaration without a prototype is deprecated in all versions of C (fix available)" warnings, looks like…
menget
- 21
- 2
-2
votes
1 answer
Function with variables in C
Maybe a stupid question, but I don't understood why my program in C works with integers, but not with float.
#include
main()
{
float a, b;
a = 4.5;
b = 9.6;
printf("Result of %.2f + %.2f = %.2f", a, b, added_up(a,…
Hermann12
- 1,709
- 2
- 5
- 14
-2
votes
1 answer
change a var using pointer in a function
#include
#include
change (int i)
{
int *x;
x = &i;
printf("%d\n",*x);
*x = 7;
printf("%d\n",*x);
}
int main()
{
int i=66 ;
change(i);
printf("%d\n",i);
return 0;
}
I'm wondering how to…
91256
- 1
-2
votes
1 answer
What are pointers in C
I have this task:
Make corrections in the maxmin.c program so it compiles itself and
works correctly (finds max and min out of 3 integer numbers and
displays them on the screen). Do not change the structure of the
program. In case of incorrect…
bowtie
- 29
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