char* new and delete [] error when a string is assigned

Question

I need a C++ refresher. Why does this gives a memory exception?

pear = new char[1024];
pear = "happy go lucky";
delete [] pear; // exception

Answer 1

pear = new char[1024];

Memory for 1024 character is allocated from heap and pear points to the start of it.

pear = "happy go lucky";

pear now points to the string literal which resides in the read-only segment and the previously allocated memory is leaked.

delete [] pear;

You try to free the read-only string, which is a undefined behaviour manifested as a runtime exception.

Answer 2

pear = "happy go lucky";

This replaces the pointer allocated by new char[]. So now your delete[] pear tries to free the statically allocated string.

That's bad. You can only delete what you allocate with new. And since you overwrote (and lost) that pointer, you can't delete it.