Set array size during run time.

Question

Today while trying out some stuff in C I found out that it is not possible to set the size of an array during runtime in a direct way. Is there any easy way around that? I have asked Google of course, but I don't understand much of the proposed solutions, yet. Please help! 😊

Here an example of what I would like to do in C:

int size;
scanf("%d",&size);
int array[size];

But this of course does not work.

Answer 1

You can use malloc for this.

int* arr = malloc(size*sizeof(int));

This allocates memory depending on the type and number of elements.
You can access the elements in the same way as in normal arrays.

https://code.sololearn.com/cz3aHfpb4MyL/?ref=app

Answer 2

It just needs a bit practice. It's not that hard anymore after using it a few times. But no need to hurry. I just wanted to add the link because it felt a bit incomplete to post how to create dynamic arrays in runtime without saying anything about multidimensional arrays ^^

Answer 3

Thank you soo much for the fast answer. That is way better than the solutions I found! 👍

Answer 4

Just for completion here is a how-to for multidimensional arrays:
http://www.equestionanswers.com/c/dynamic-2d-3d-array.php

Answer 5

Is it like pointers pointing to pointers? 😵 I think I'll need a little bit more time for the second part (the link). I haven't had much practise with pointers yet. - A little bit in Perl but it somehow seemed easier there...