C – freeing structs

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Simple answer : free(testPerson) is enough .

Remember you can use free() only when you have allocated memory using malloc, calloc or realloc.

In your case you have only malloced memory for testPerson so freeing that is sufficient.

If you have used char * firstname , *last surName then in that case to store name you must have allocated the memory and that’s why you had to free each member individually.

Here is also a point it should be in the reverse order; that means, the memory allocated for elements is done later so free() it first then free the pointer to object.

Freeing each element you can see the demo shown below:

typedef struct Person
{
char * firstname , *last surName;
}Person;
Person *ptrobj =malloc(sizeof(Person)); // memory allocation for struct
ptrobj->firstname = malloc(n); // memory allocation for firstname
ptrobj->surName = malloc(m); // memory allocation for surName

.
. // do whatever you want

free(ptrobj->surName);
free(ptrobj->firstname);
free(ptrobj);

The reason behind this is, if you free the ptrobj first, then there will be memory leaked which is the memory allocated by firstname and suName pointers.

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