Array

Definition

An array is a single or multidimensionnal table of data.

Each data is called an element and is accessed by its position. The position is called INDEX.

Examples :

A string is a one dimension array :

chaine : array[1..8] of char;

A chessboard could be an 2D array

chessboard : array[1..8,1..8] of byte;

How to declare an Array

As seen previously, an array is defined with the keyword ARRAY.

An array could be a variable, a constant or a type. The type of the data must be declared

Array as a variable :

Example :

VAR

myTab : array[1..10] of byte;//10 bytes array

Array as a constant :

Example :

       CONST

               Days : array[1..7] of string =('Mon','Tue','Wed','Thu','Fri','Sat','Sun');

Array as a type :

Example :

       TYPE

               TDays : array[1..7] of string;

       CONST

               Days : TDays = ('Mon','Tue','Wed','Thu','Fri','Sat','Sun');

How to use an Array

Access to the cells

The index helps to access to the different cells.

Example (with the array Days) :

For i:=1 to 7 DO writeln(Days[i]);

Change a data value

Example (with the array myTab) :

myTab[2]:=10;

Array of a record

It's also possible to declare an array of a record :

Example :

TYPE TVerb = RECORD

               infinitive:string[25];

               past:string[25];

               participle:string[25];

       end;

               

VAR

       irregular : array[1..100] of TVerb;