Question

I have the following scenario,

class foo
{
  ...
  private:
   char *_test;
};

void foo::setTest()
{
  if( 0 != _test ) delete [] _test;
}

The function setTest throws an error when called, as it trying to delete _test when it has not yet been assigned. This is happening because _test is not set to 0X0.

Can anyone help me to understand this?

Answer 1

You should initialize _test with NULL in the constructor.

Like:

foo:foo {
 _test = NULL;
}

If you don’t _test will have garbage value.

Also as pointed by Chris, The value passed as argument to delete or (delete[]) must be either a pointer to a memory block previously allocated with new, or a null pointer (in the case of a null pointer, delete produces no effect), effectively making your NULL check redundant.