C: delete array

I'm new in c. I want to create array, and after it delete it, and then put another array into it. How can I do it?

2 Answers

If you are looking for a dynamic array in C they are fairly simple.

1) Declare a pointer to track the memory,
2) Allocate the memory,
3) Use the memory,
4) Free the memory.

int *ary; //declare the array pointer int size = 20; //lets make it a size of 20 (20 slots) //allocate the memory for the array ary = (int*)calloc(size, sizeof(int)); //use the array ary[0] = 5; ary[1] = 10; //...etc.. ary[19] = 500; //free the memory associated with the dynamic array free(ary); //and you can re allocate some more memory and do it again //maybe this time double the size? ary = (int*)calloc(size * 2, sizeof(int)); 

Information on calloc() can be found here, the same thing can be accomplished with malloc() by instead using malloc(size * sizeof(int));

It sounds like you're asking whether you can re-use a pointer variable to point to different heap-allocated regions at different times. Yes you can:

void *p; /* only using void* for illustration */ p = malloc(...); /* allocate first array */ ... /* use the array here */ free(p); /* free the first array */ p = malloc(...); /* allocate the second array */ ... /* use the second array here */ free(p); /* free the second array */