define Macro

#define <macro> <value>

Define is a Macro, you can think of a way to tell the processor that, whenever the defined name is encountered, it should be replaced by the value or content that follows. It's similar to a variable with a set initial value, but this variable has no type and accepts anything. You can check if a Macro is defined using #ifdef preprocessor keyword.

ifdef Macro test

#ifdef <macro>
  //content
#endif

#ifndef <macro>
  //content
#endif

Test if macro is defined or undefined and only pass the content for the compiler if the test is true.

ifver Version Checking

If you are writing a script module, you may need to check which version of AGS the user of your module is using. For this purpose there are two directives:

#ifver <version>
  // this code will be passed if user's AGS version is above or equal to <version>
#endif

#ifnver <version>
  // code will be passed if user's AGS version is below <version>
#endif

Note that this ability was only added in 2.72, so you cannot use the #ifver checks if you want your module to work with earlier versions than this. Example:

#ifver 2.72
// do stuff for 2.72 and above
#endif
#ifnver 2.72
// do stuff for 2.71 and below
#endif

See also: Version Checking Keyword

region code folding

#region
  // some code
#endregion

You can wrap a code between lines containing #region and #endregion to create a section used for code folding. In the AGS Editor you can use this to hide sections of your code you don't need to see by using the + button at the left side of the script editor.

error throw compile error

#error

User defined compile-time error (with message).

legacy commands

#sectionstart

#sectionend

These two preprocessor commands do nothing, they are ignored legacy commands from pre-3 era. They are valid keywords so there you have it.

See: Scripting Languange