Question

I want to declare a pointer to an integer array in the header file for my class. I have

private:
 int *theName;

and then in the constructor

theName = new int[10];

will this work? Is there another way to do this so you have a pointer to an array?

I thought int *theName created a pointer to an integer not an integer array, if this creates a pointer to an integer array how do you create a pointer to just an integer?

Also in the destructor can I call

delete theName; theName = NULL;

Will that delete theName integer array object and then point theName to null in memory?

Thanks

Answer 1

Four things:

• One, yes that is how you make a pointer to an array. Notice that there’s no difference between a pointer to an integer and a pointer to an integer array; you can think of an integer as an array of one element. You can still use x[0] if x is a pointer to an integer, and you can still use *x if x is a pointer to an array, and they work the same.

• Secondly, you have to use delete[] theName, not delete theName. Wherever you use new you have to use delete, and wherever you use new[] you have to use delete[]. Also, it is unnecessary to set theName = NULL because after the destructor is run, you can’t access theName any more anyway.

• Thirdly, when you write a class that manages resources, you need to write a copy constructor, move constructor, copy assignment operator and move assignment operator.

• Fourthly, unless you are just doing this as a didactic exercise, you should really use std::vector. It has many advantages and no real disadvantages. And you don’t even have to write the four other constructors if you use vector.