This script demonstrates how to work with strings. This is a basic Caesar cipher example.
var i,index:byte; s:string; begin write ('Verschiebeindex eingeben: '); readln (index); write ('Wort eingeben: '); readln (s); for i:=1 to length(s) do s[i]:=chr(ord(s[i])+index); write ('Neue String ist: ',s); readln; end.
The indice of the cipher and the string to modify are first read from the keyboard. Then, a FOR statament passes through each of the string's chars and modifies them by adding indice to their ASCII code, thus pushing them indice chars further in the ASCII code.