Differences between the languages Borland Delphi

Because Borland Delphi is a widely used version of Pascal, it is useful to compare the two languages. Note that here are presented only the differences between Borland Delphi and the basic ISO 7185 standard. Undiscussed are any extensions provided by Borland Delphi. In other words, this section answers the question "why doesn't my standard Pascal program run under Borland Delphi?", and perhaps "what can I write in Borland Delphi that will also be compatible with the ISO 7185 standard?".

1. Procedures and functions may not appear as parameters (it is true that it can be done, but a non-standard syntax must be used).

2. Goto statements cannot reference targets outside procedure/function bodies (so called "intraprocedural gotos").

3. No file buffer variable handling. Standard Pascal has file "buffer variables", and "get" and "put" procedures to operate on them. This functionality is not present in Borland Delphi.

4. No "sized" dynamic variable allocation. Given a variant record, the size of a particular variant cannot be specified as per the standard. I.e., the following statement is invalid:

new(p, t)

Where t is a variant record tag type.

5. The functions "pack" and "unpack" are not implemented.

6. { and (*, } and *) are not synonyms of each other as required by the standard. Ie.:

{ comment *)

is not valid in Borland Delphi (Delphi uses the scheme of allowing the different comment types to indicate nested comments).

7. It is not possible to construct a standard program without compiler directives. At minimum:

{$APPTYPE CONSOLE}

is required.

8. Does not replace eoln with space as the standard requires. When reading through the end of a line, the eoln character is supposed to be replaced with a space in ISO 7185. Instead, reading through eoln in Borland Delphi gives the character code for carriage return (13), followed by line feed (10).

9. Numbers and booleans are not printed out in their "default" field widths, but are printed in the minimum amount of space. For example:

write('>', 5, '<');

Outputs:

>5<

in Delphi, but:

> 5<

(spaces depend on compiler integer width) in ISO 7185.

For booleans:

write('>', true, '<');

outputs:

>true<

in Delphi, but:

> true<

In ISO 7185.

Comparision of Pascal and Borland Delphi

Pascal is a programming language, developed in 1970 by Niklaus Wirth.

An alternative dialect was created by Borland Corporation. Their language went through several versions and names, such as Turbo Pascal, Borland Pascal, and finally Delphi Pascal.

This page briefly goes over the differences between those dialects of the language.

The title of this page "Comparison between Pascal and Delphi" was chosen because Borland uses the name "Delphi" exclusively for their version of the language. It is correct to refer to "Pascal" in general as Niklaus Wirth's original language (and derivatives) and Borland's dialect as "Delphi". When referring to Borland's previous dialects, the terms "Turbo Pascal", and "Borland Pascal" apply.

The Term ISO 7185 or ISO 7185 Pascal is used here as synonymous with Niklaus Wirth's programming language Pascal. The ISO 7185 standard is the standardized version of Niklaus Wirth's language, as he has stated several times.