Editing Pointer (computer programming) (section)

==Formal description==
In [[computer science]], a pointer is a kind of [[Reference (computer science)|reference]].

A ''data primitive'' (or just ''primitive'') is any datum that can be read from or written to [[computer memory]] using one memory access (for instance, both a ''[[byte]]'' and a ''[[Word (computer architecture)|word]]'' are primitives).

A ''data aggregate'' (or just ''aggregate'') is a group of primitives that are [[Logical address|logically]] contiguous in memory and that are viewed collectively as one datum (for instance, an aggregate could be 3 logically contiguous bytes, the values of which represent the 3 coordinates of a point in space). When an aggregate is entirely composed of the same type of primitive, the aggregate may be called an [[Array data structure|''array'']]; in a sense, a multi-byte ''word'' primitive is an array of bytes, and some programs use words in this way.

In the context of these definitions, a ''byte'' is the smallest primitive; each [[memory address]] specifies a different byte. The memory address of the initial byte of a datum is considered the memory address (or ''base memory address'') of the entire datum.

A ''memory pointer'' (or just ''pointer'') is a primitive, the value of which is intended to be used as a memory address; it is said that ''a pointer points to a memory address''. It is also said that ''a pointer points to a datum [in memory]'' when the pointer's value is the datum's memory address.

More generally, a pointer is a kind of [[Reference (computer science)|reference]], and it is said that ''a pointer references a datum stored somewhere in memory''; to obtain that datum is ''to dereference the pointer''. The feature that separates pointers from other kinds of reference is that a pointer's value is meant to be interpreted as a memory address, which is a rather low-level concept.

References serve as a level of indirection: A pointer's value determines which memory address (that is, which datum) is to be used in a calculation. Because indirection is a fundamental aspect of algorithms, pointers are often expressed as a fundamental [[data type]] in [[programming language]]s; in [[Static types|statically]] (or [[Strong and weak typing|strongly]]) typed programming languages, the [[Type system|type]] of a pointer determines the type of the datum to which the pointer points.