A variable length array is an array in C99 and other languages whose size is unknown at compile time; instead, it's determined at runtime.
Questions tagged [variable-length-array]
413 questions
2
votes
3 answers
stack space for a vector that its size is given at runtime? (C code)
Supose this C code:
int main(){
int n;
scanf("%d\n", &n);
int a[n];
int i;
for (i = 0; i
isma
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2
votes
5 answers
Can I use an integer variable to define an arrays length?
Can I use a variable to define an array's size?
int test = 12;
int testarr[test];
Would this work, I don't want to change the size of the array after initialization. The int test's value isn't known at compile time.
Björn Max Jakobsen
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2
votes
2 answers
Point of initializing a pointer to an array with another array
This pointer to an array is initialized with another array. What is it trying to accomplish?
float range_[] = {0, 180};
const float* range[] = {range_};
I'm trying to consolidate them into a class, and C++ is finicky about putting variable length…
Oren Bell
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2
votes
5 answers
What is the best way to make 2 dimensional array in C
I want to make a 2 dimensional array in C.
I know 1 way to make it like this.
#include
void my_func(int **arr)
{
printf("test2: %d\n", arr[0][1]);
}
int main(void)
{
const int row = 3;
const int col = 4;
…
Terry
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2
votes
3 answers
How are Variable Length Array instructions generated?
Variable length arrays are supported in C:
int main(){
int num = 5;
int arr[num];
return 0;
}
I understand that arr is allocated during runtime. How is this accomplished?
Does it call a C runtime function to allocate the byes? As the…
user13373366
2
votes
1 answer
Passing 2D array to a funciton in c & c++
I tried same program for C & C++ i.e. passing 2D array to a function.
The following program is working in C,
but not working in C++,
Please explain why so ?
IN C
#include
void pass(int n, int arr[][n]) // or void pass(int n, int…
Vaibhav Punia
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2
votes
2 answers
Why does this OpenMP code work on Linux, but not Windows?
Edit: solved! Windows limits the stack size to where my buffer does not fit; linux does not (additionaly I was accessing memory outside of my array... oops). Using gcc, you can set the stack size like so: gcc -Wl --stack,N [your other flags n stuff]…
AnnoyinC
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2
votes
2 answers
VLA prototype and multidimensional array argument
I created a C99 VLA function as such :
void create_polygon(int n, int faces[][n]);
I want to call this function in another function where I would allocate my two-dimensional array :
void parse_faces()
{
int faces[3][6];
create_polygon(6,…
explogx
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2
votes
5 answers
myArray[N] where N = 1,000,000 returns an error whereas myArray[1,000,000] doesn't
File extension: .cpp
I have the following code:
int main() {
int N; cin >> N;
int myArray[N];
return 0;
}
I get an error when I'm trying to run that program if I input N as 1,000,000. However, when I set myArray[N] to myArray[1000000],…
Richard
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2
votes
1 answer
C99 How to cast simple pointer to a multidimensional-array of variable length?
In my function bodies reduce() and initialize(...) I want to work with the array globalArray as a three-dimensional one, where the dimensions are not known until runtime.
How do I cast the globalArray pointer to a variable-length array (pointer) and…
NoahR
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2
votes
2 answers
Return variable length array in Numpy C-extension?
I have made some Numpy C-extensions before with great help from this site, but as far as I can see the returned parameters are all fixed length.
Is there any way to have a Numpy C-extension return a variable length numpy array instead?
c00kiemonster
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votes
2 answers
How does C99 handle being unable to create a variable length array at run time?
I program embedded systems. One golden rule is that we never call malloc(); all data must be statically allocated at compile time.
Hence, I am not really familiar with Variable Length Arrays, which were introduced with C99.
The concept seems clear…
Mawg says reinstate Monica
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2
votes
1 answer
variable length multidimensional arrays
I did this program for a homework and it crashes without any error when run.
Also after correcting it, any suggestions to increase the efficiency of my coding approach are appreciated.
First I declared m,n,p,q as global variables an I passed only…
loki47_ch
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2
votes
6 answers
How to handle an dynamic array?
I want to show up the names of the members of an array "path" in my console.
console.log("start: ", path[0].name, "second: ", path[1].name, "third: ", path[2]name, ....)
But the problem is, that my array always changes it's size (clicking…
Derick Kolln
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2
votes
2 answers
What is the cost of creating large local arrays on the stack in C and C++?
Let's say I have a function called from within a tight loop, that allocates a few large POD arrays (no constructors) on the stack in one scenario, vs. I allocate the arrays dynamically once and reuse them in each iteration. Do local arrays add…
mojuba
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