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
1
vote
1 answer
Segfaults on initialization of array of pthread_t
I have a program that takes input n from the command line, and, as part of its operation, tries to call the following code:
pthread_t threads[n*n];
Now, for any n <= 1023, this works fine, but the moment I try to use n > 1023, I get a segfault. It…
Koz Ross
- 3,040
- 2
- 24
- 44
1
vote
1 answer
Initializing a variable length array to zero
int x = 750;
int i = 0;
while (pow(2, i) < x) {
i++;
}
printf("i is currently %d\n", i);
int array[i];
while (i > 0){
i--;
printf("The value of array %d is %d\n", i, array[i]);
}
When I do this, it creates some really crazy values.…
Farion
- 21
- 1
- 3
1
vote
2 answers
Creating legend of variable length datasets+ignoring empty cells
I'm trying to plot some monthly statistics that span over 2 years, where 1 year has only one month of data and the other has 11 months of data. Where I'm having trouble is in the legend label, when I am filling out the label it takes the one month…
user1332577
- 362
- 5
- 17
1
vote
2 answers
How to make a program declare variable number of indefinite size arrays
This might sound crazy but I was wondering if it is possible to make a program declare n number of arrays of the type array[] in a loop using C/C++. For example, sample this pseudo-code:
input int _n_
run loop for _n_ times such that:
declare…
Quirk
- 1,305
- 4
- 15
- 29
1
vote
1 answer
Working with arrays and variable length formal parameters. (java:38: error: '.class' expected)
I am not finished working on this program, so I know there may be other mistakes. I am currently getting the '.class' expected error, and for some reason I can't see that mistake.
I am using jGrasp and this is a project for my Intro to Java class. …
Nat
- 37
- 2
- 8
1
vote
1 answer
Stack Overflow Behaviour in Native Languages
I'm curious to why most natives languages, including C,C++ and D, doesn't define stack-overflow behaviour. Is it because it would require instrumenting every stack variable allocation and function call which, in turn, would make the code unusably…
Nordlöw
- 11,838
- 10
- 52
- 99
1
vote
1 answer
Constant structure with flexible array members
Please consider the following two structures:
typedef struct {
int num_data;
char * name_data;
int data[];
} part_t;
typedef struct {
int num_parts;
char * name_parts;
part_t parts[];
} container_t;
Ideally, I would be…
lupin3
- 11
- 2
0
votes
4 answers
C Dynamic Array Size
Hello I am new to coding and was just wondering why the below code:
#include
int main() {
for(int i = 0; 1 ; i++) {
char x;
char z[1+i];
x=getchar();
if (x == '\n'){
*(z+i) = '\0';
printf("%s",z);
…
soda2718
- 1
- 2
0
votes
2 answers
C Use an array variable in a function parameter?
I have a 2D array of strings char* d2Array[valueA][valueB].
This works fine, I am able to fill it with strings and access them. There is an issue when passing it to a function. You need to specify the second size parameter (i.e. void aFunction(char*…
Ethan Gascoigne
- 55
- 2
- 8
0
votes
1 answer
Taking Input an array in C++ using cin directly by operator overloading
#include
#include
#include
template
std::istream& operator>>(std::istream& in, T (&arr)[Size])
{
std::for_each(std::begin(arr), std::end(arr), [&in](auto& elem) {
in >>…
mayank garg
- 13
- 1
0
votes
2 answers
How do I store integers in an array in c?
I am trying to make a programm that turns a string into binary.
int len = strlen(word);
int array2[len] = ascii_v(word, len);
int ascii_v(string w, int l)
{
int array1[l];
for (int i = 0, i < l; i++)
{
array1[i] = word[i];
…
Ricci2003
- 1
- 1
0
votes
0 answers
Values in an Array within a Dynamic Array of Structs being overwritten by previous values
To preface: I am new to C and still learning the best way to efficiently code in C.
I'm trying to create an dynamic array of structs. I have an array within the struct however the values within the array are being overwritten by the values that come…
Skyttlez
- 1
0
votes
3 answers
C How to create an 2d array of characters?
So would like to create an 2D array of characters for testing purposes. Here is my code.
const int rows = 4;
const int columns = 6;
//char field[rows][columns];
//fill_field(rows,columns,field);
char field[rows][columns] = {
…
tomastrue
- 11
- 2
0
votes
1 answer
With Construct-Package: RepeatUntil total lenght of subconstruct
Let's say I have:
numResults (Int16ul)
resultItems[numResults]
where the resultItems is constructed like:
ID (does not always increase)
strLen
my_str[strLen]
Now I understand, that I have to use RepeatUntil but how the repeathandler is supposed to…
Startin Mohanzl
- 1
- 3
0
votes
1 answer
In C++, why can't I declare an array like this: int array[vector.size()]?
I want to convert a float vector to a float array in C++ 20. I searched online and found this solution:
#include
#include
#include
int main()
{
std::vector input({ 1, 2, 3, 4, 5 });
int…
Pepis
- 9
- 1