Types ‘Char’ and ‘Boolean’. Boolean Operators

Abstract

So far, we have formally introduced two types of data. Both of them are numerical: INTEGER and REAL. We have also discussed and demonstrated the output of strings (or, to be more specific, character strings) of which characters are the single elements (letters of the alphabet, decimal digits 0–9, punctuation marks, mathematical signs and other symbols). The ability to handle characters and strings of characters is a powerful feature of computers. It makes word processing possible and it has many other uses. In fact the world’s first digital electronic data processing machine, ‘Colossus’, designed by the British Post Office in 1943 to assist in cracking enemy codes, was a character processor and had no numerical computing facilities.