Difference between revisions of "Data type"

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([cardinal]] - an unsigned whole number)
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* [[Integer|integer]] - a whole number.  FPC currently uses 4 bytes for integers
 
* [[Integer|integer]] - a whole number.  FPC currently uses 4 bytes for integers
 
* [[real]] - a number which may have a decimal point and possibly an exponent
 
* [[real]] - a number which may have a decimal point and possibly an exponent
* [[cardinal]] - a variable which has a group of values to which it may hold only one;
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* [[cardinal]] - an unsigned  whole number,ie it must be positiv
 
* [[set]] - a collection of related elements; size depends on number of elements  
 
* [[set]] - a collection of related elements; size depends on number of elements  
 
* [[Pointer|pointer]] - a reference to a location in memory, generally used for dynamic variables
 
* [[Pointer|pointer]] - a reference to a location in memory, generally used for dynamic variables

Revision as of 16:53, 5 May 2007

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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 positiv
  • 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.