CODEWITHSUNDEEP
c
Baz
Baz

Reputation: 13145

Returning a pointer to a struct pointing to a string

Is this the correct way to create a string in this case. 

Foo* create()
{
  Foo *foo = malloc(sizeof(Foo));
  foo->name = strdup("Foo");
  return foo;
}

I will later have to delete both foo and foo->name myself.

Upvotes: 1

Views: 84

Answers (2)

Bart
Bart

Reputation: 1663

The object allocation isn't entirely correct (you should cast to Foo* and not to mystruct). The string allocation is correct, but maybe not exactly what you want.

The strdup() function actually calls malloc() for you, and you only need this construction if you want to modify the string at a later time (and don't increase its length!!!). You should not forget to call free() on the string when you're disposing the Foo object.

If foo->name is for read-only purposes, declare foo->name as a const char * and just write foo->name = "Foo"; to initialize it.

EDIT: Also note that strdup() might return NULL, and you should check for it! If it is I would than just assert() on it, because out-of-memory errors are pretty unrecoverable. Don't try to handle such kind of errors. This also counts for allocating the Foo object too.

Upvotes: 2

Constantinius
Constantinius

Reputation: 35069

It is correct, but you don't have to cast the return pointer of malloc (and you shouldn't).

Upvotes: 0

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