This chapter is about data types, probably not all of them though.

Data type

Defining a collection of data objects .and a set of predefined operations on those objects.

A descriptor is the collection of the attributes of a variable

An object represents an instance of a user-defined (abstract data) type

Primitive data types => data types that is widely available in most languages. Such as:  integer, floating point, complex, decimal, boolean, and character.

Character String types =>sequences of character

User-Defined Ordinal Types => Range of the possible values

Enumeration Types => All possible values are provided in definition

Subrange Types => An ordered contiguous subsequence of an ordinal type

Array Types => Homogeneous aggregate of data elements in which an individual element is identified by its position in the aggregate

Record Types => Possibly heterogeneous aggregate of data elements in which the individual elements are identified by names

Tuple Types => Similar to a record, except that the elements are not named

List Types => Delimited by parentheses and use no commas

Union Types => Variables are allowed to store different type values at different times during execution

Pointer and Reference Types => Consisting of the memory addresses and special value

Type Checking => An action to evaluate the operands are able to be executed by operators.

Strong Typing => The variables which will be defined must be given a data types or it may turn out as error.