C Memory and structs

A struct groups related values. malloc asks for memory at run time and free gives it back. Always free what you allocate.

ExampleC

#include <stdio.h>
#include <stdlib.h>

struct Point {
  int x;
  int y;
};

int main(void) {
  struct Point p = {3, 4};
  printf("(%d, %d)\n", p.x, p.y);

  struct Point *pp = &p;
  printf("%d\n", pp->x + pp->y);

  int *nums = malloc(3 * sizeof(int));
  for (int i = 0; i < 3; i++) nums[i] = (i + 1) * 10;
  printf("%d %d %d\n", nums[0], nums[1], nums[2]);
  free(nums);
  return 0;
}

Output

(3, 4)
7
10 20 30

Quick check

What must you do with memory from malloc?

Nothing, it is automaticfree it when finishedDeclare it const

Finish the quick check (and any code exercise) to complete this lesson, or mark it done yourself.

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