指定的存储位置中没有指针。 Delete op有什么问题？

Question

I am trying to make an example for char pointers and use of delete operator. Code is very simple:

char name[] = "subject";
char *nameptr = name;
cout <<"&nameptr: " <<&nameptr<< endl;
delete [] nameptr;

and I keep getting this error:

*** glibc detected ***  free(): invalid pointer: 0xbf9e4194 ***

and I know nameptr points out to location 0xbf9e4184, from the output. There is no pointer points out to that location (0xbf9e4194). I believe it's something to do with my use of delete but I couldn't figure it out.

Answer 1

You should only call delete or delete [] on memory allocated with new or new [] , respectively. There's no need to free string literals like "subject" .

Answer 2

Examine your code statement by statement:

Here you have an array of characters, containing "subject":

char name[] = "subject";

Here you define a pointer, pointing to the aforementioned array:

char *nameptr = name;

Here you delete[] something that you did not allocate using new[] (in fact, name was not allocated using new[] , you didn't write: char * name = new char[...] ):

delete [] nameptr;

So, an error is (correctly) detected, because you tried to free something that was not allocated on the heap using new (or malloc ).