Specifies the beginning of the fall-through case in a set of preprocessor conditions.
This macro preprocessor directive specifies the beginning of the fall-through case in a set of preprocessor conditions. It can follow #ifDef, #if, or #elseIf. It is followed by #endif. It has the form:
// subsequent indented lines for specified actions
The #else directive keyword should appear on a line by itself. Anything following #else on the same line is considered a comment and is not parsed.
For an example of #else with #if, see that directive; for an example with #endif, see that directive.
If #else appears in method code and has an argument other than a literal value of 0 or 1, the compiler generates code in subclasses (rather than invoking the method in the superclass). To avoid generating this code, test conditions for a value of 0 or 1, which results in simpler code and optimizes performance.