A pointer is a variable that stores the address of another variable in memory. Harold Lawson invented the pointer concept in 1964 and introduced it in PL/I, allowing linked lists to be implemented more flexibly in a high-level language. Pointers are used to manage data structures like lists, queues and trees by providing start, end and stack pointers that can be absolute memory addresses or relative offsets. Pointers are supported in languages like PL/I, C, C++ and Pascal and are primarily used to construct references and pass data between different parts of a program.

1. Hello friend

2. A pointer is a variable whose value is the address of another variable, i.e., direct
address of the memory location. Like any variable or constant, you must declare a
pointer before using it to store any variable address.

3. History of pointer ?
Harold Lawson is credited with the 1964 invention of the pointer.[2] In 2000, Lawson was
presented the Computer Pioneer Award by the IEEE “[f]or inventing the pointer variable and
introducing this concept into PL/I, thus providing for the first time, the capability to flexibly
treat linked lists in a general-purpose high level language”.[3] His seminal paper on the
concepts appeared in the June, 1967 issue of CACM entitled: PL/I List Processing. According
to the Oxford English Dictionary, the word pointer first appeared in print as a stack pointer
in a technical memorandum by the System DevelopmentCorporation.

4. Use in data structures ?
When setting up data structures like lists, queues and trees, it is
necessary to have pointers to help manage how the structure is
implemented and controlled.Typical examples of pointers are start
pointers, end pointers, and stack pointers.These pointers can
either be absolute (the actual physical address or a virtual address
in virtual memory) or relative (an offset from an absolute start
address ("base") that typically uses fewer bits than a full address,
but will usually require one additional arithmetic operation to
resolve).

5. Uses
Pointers are directly supported without restrictions in languages such
as PL/I, C, C++, Pascal, FreeBASIC, and implicitly in most assembly
languages.They are primarily used for constructing references, which
in turn are fundamental to constructing nearly all data structures, as
well as in passing data between different parts of a program.

6. Thank you
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