Magic Variables
Introduction
Magic variables are engine maintained variables that serve a specific purpose within a given scope and are often used by the engine to push data to a given script or code fragment. They are usually no longer present after leaving the scope (e.g. after code execution or after a forEach statement).
See also: this
Usage
_this
probably the most frequently used magic variable, which is used to make arguments of a script call (call, exec, execVM, spawn) visible and accessible to the script.
_x
represents the current element during a loop with: apply, count, configClasses, configProperties, findIf, forEach, select.
_forEachIndex
represents the (zero-based) index of a forEach _x.
thisList, thisTrigger
variable defined by Triggers, which are however only accessible within the activation or deactivation script.
_exception
[Exception handling]] using a try..catch statement declares this variable which contains details about the thrown exception in the try block.
_thisScript
is the spawned script handle from within itself since Arma 3.
_thisEventHandler
Since Arma 3 v.1.63.137807, the script handle (not the EH index!) for Event Handlers added with addEventHandler or addMPEventHandler.
_pos,_alt,_shift,_units
See onMapSingleClick