Data Types

Data types are types of data e.g. text data. For those of you who are familiar with Databases, a data type is like a field type. If you want to store any type of data then you need to tell Delphi what data type you need.

These are some of the data types (most used) you can use in Delphi:

Integer - Whole number e.g. 5.
Extended - Decimal number e.g. 5.5.
Char - One character e.g. 'A'.
String - A string of characters e.g. 'Delphi'.
PChar - A string for use with Win API (Applications Programming Interface).

Object Pascal:

"Object Pascal is a high-level, compiled, strongly typed language that supports structured and object-oriented design. Its benefits include easy-to-read code, quick compilation, and the use of multiple unit files for modular programming.
Object Pascal has special features that support Delphi's component framework and RAD environment. For the most part, descriptions and examples in this language reference assume that you are using Object Pascal to develop Delphi applications.

Most Delphi developers write and compile their code in Delphi's integrated development environment (IDE). Delphi handles many details of setting up projects and source files, such as maintenance of dependency information among units. Delphi also places constraints on program organization that are not, strictly speaking, part of the Object Pascal language specification. For example, Delphi enforces certain file- and program-naming conventions that you can avoid if you write your programs outside of the IDE and compile them from the command prompt.

These Help topics generally assume that you are working in Delphi's IDE and that you are building applications that use the Visual Component Library (VCL). Occasionally, however, Delphi-specific rules are distinguished from rules that apply to all Object Pascal programming." -Delphi Help

Object Pascal is the language that Delphi uses. These are the basics rules of Object Pascal:

Strings are always surrounded with a single-quote (') e.g. 'Delphi',
Each statement ends with a semi-colon (;),

Note

If you will place a ';' directly before an ELSE in an IF-ELSE statement.
The reason for this is that the ';' is treated as a statement separator, not a statement terminator - IF-ELSE is one statement, a ';' cannot appear in the middle (unless you use compound statements).

Object Pascal is not a case-sensitive language, so the command ShowMessage for example could be written in any case e.g. ShowMessage, showmessage, SHOWMESSAGE, sHOwMessAge or any other case.