7 Pointers and Dynamic Memory Free Online FlashCards

What does a pointer store?

A pointer is an object that stores an address, allowing indirect access to another object or function.

What does the `&` operator produce?

The address-of operator `&` produces a pointer to an object, such as `int* address = &score;`.

What does unary `*` do to a pointer?

The unary `*` operator dereferences a pointer, accessing its target. It can read the target or modify it when the pointer permits modification.

When is pointer dereferencing valid?

Dereferencing is valid only when the pointer points to a live object or function. Null, dangling, uninitialized, and otherwise invalid pointers must not be dereferenced.

How does pointer arithmetic scale movement?

Within an array, `p + 1` advances to the next element, not necessarily the next byte. The step is scaled by the pointed-to type.

Where is array pointer arithmetic defined?

Pointer arithmetic is defined within one array, including the position one past its end. A one-past pointer may be formed but must not be dereferenced.

What does subtracting same-array pointers produce?

Subtracting two pointers into the same array gives the number of elements between them, such as `&numbers[4] - &numbers[0]`, which equals 4.

What does an array name usually convert to?

In most expressions, an array name converts to a pointer to its first element, so `values` is equivalent to `&values[0]` in that context.

How do arrays and pointers differ?

An array owns a fixed number of elements and includes its size in its type; a pointer only stores an address and does not remember the element count.

What does `nullptr` represent?

`nullptr` represents a pointer that points to no object or function. It may be compared, copied, or assigned, but it must not be dereferenced.

What is a dangling pointer?

A dangling pointer refers to an object whose lifetime has ended. Returning the address of a local variable creates this problem after the function returns.

Which deletion matches `new` and `new[]`?

A single object allocated with `new` must be released with `delete`; an array allocated with `new[]` must be released with `delete[]`.