A data type is a classification of a variable or constant. There are certain data types that are predefined by any Pascal compiler (because you need them to make everything else). These are:
- byte - an unsigned number in the range 0 to 255.
- char - Single character.
- integer - a whole number. FPC currently uses 4 bytes for integers.
- real - a number which may have a decimal point and possibly an exponent.
- cardinal - an unsigned whole number,ie it must be positive.
- set - a collection of related elements; size depends on number of elements.
- pointer - a reference to a location in memory, generally used for dynamic variables.
- record - a combination of the above data types collected together.
- object - a hybrid entity that may contain data and procedures to manipulate that data.
Other data types are generally made with some combination of the above. FPC adds additional data types.
|Simple Data Types||Boolean | Byte | Cardinal | Char | Currency | Extended | Int64 | Integer | Longint | Pointer | Real | Shortint | Smallint | Word|
|Complex Data Types||Array | Class | Record | Set | String | ShortString|