16/32 Bit Strings

Question:
Is there a difference in the way that strings are passed between an application written in Delphi 1.0 and a DLL and between an application written in Delphi 3.0 and a DLL? For example, are the strings in Delphi 3.0 null terminated?

Answer:
Yes, there is a definite difference between strings in Delphi 1.0 and Delphi 3.0. Delphi 1.0 strings are traditionally ShortStrings–nothing more than character arrays of 256 bytes. Delphi 2.0 (and later versions) strings are AnsiStrings, which are actually pointers to null-terminated strings. Furthermore, AnsiStrings have a negative offset that contains the “length code” as opposed to ShortStrings that have a zero-offset that contains the “length byte.” What does this mean? Well, the length code of an AnsiString is a 32-bit code, which means that it can be as large as 4GB. AnsiStrings in Win32 can be as large as that. On the other hand, since the length byte of a ShortString is only 8-bits, the largest value it can be is 256. So there are fundamental differences between strings in version 1 and 2+. Based on what I explained above, the Delphi 3.0 string is not really null-terminated. However, the data that the string pointer variable points to is null-terminated. So to answer your question, strings passed in an application written in the different versions of Delphi are handled differently by virtue of their very different natures.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS

homes in the real estate industry

Exploring the Latest Tech Trends Impacting the Real Estate Industry

The real estate industry is changing thanks to the newest technological advancements. These new developments — from blockchain and AI to virtual reality and 3D printing — are poised to change how we buy and sell homes. Real estate brokers, buyers, sellers, wholesale real estate professionals, fix and flippers, and beyond may