Primitive type

In computer science, primitive types, as distinct from composite types - are datatypes provided by a programming language as basic building blocks. Depending on the language and its implementation, primitive types may or may not have a one-to-one correspondence with objects in the computer s memory.

Primitive types are also known as built-in types or basic types .

The actual range of primitive types that is available is dependent upon the specific programming language that is being used. For example, in C (programming language), String (computer science) are a composite datatype, whereas in modern dialects of Basic programming language they are a primitive datatype.

Typical primitive types may include:

Character (computing) (character, char);

Integer (computer science) (integer, int, short, long) with a variety of precision (computer science);

floating-point number (float, double, real, double precision);

Fixed-point arithmetic (fixed) with a variety of precision (computer science) and a programmer-selected Scale (order of magnitude).

Boolean datatype having the values true and false.

string (computer science) (string), a sequence of characters, which can be of zero length – containing no characters – if desired);

reference (computer science) (also called a Pointer or handle ), a small value referring to another object, possibly a much larger one.

More sophisticated types which can be primitive include:

Tuples in ML programming language

Linked lists in Lisp programming language

complex numbers in Fortran programming language, C programming language#C99, Python programming language

rational numbers in Lisp programming language

first class functions, Closure (computer science)s, Continuations in Functional programming languages such as Lisp programming language and ML programming language

One usually expect operations on primitive types to be the fastest language contructs there are. Integer addition, for example, can be performed as a single machine instruction, and some central processing unit offer specific instructions to process sequences of characters with a single instruction. In particular, the C programming language standard mentions that a ``plain int object has the natural size suggested by the architecture of the execution environment . This means that int is likely to be 32 bits long on a 32-bit architecture.

Most languages do not allow the behaviour or capabilities of primitive types to be modified by programs. Exceptions include Smalltalk, which permits primitive datatypes to be extended within a program, adding to the operations that can be performed on them or even redefining the built-in operations.