How to use Preprocessing Directive #elif in C#
Description
The #else
directive establishes an alternative if #if
fails.
#else
marks both the end of the #if block and the beginning of the #else
block.
The #elif
directive means "else if".
The #elif
directive establishes an if-else-if chain for multiple compilation options.
#elif
is followed by a symbol expression.
There can be only one #endif
associated with any #if
.
If the expression is true, that block of code is compiled, and no other #elif
expressions are tested.
Syntax
The general form for #elif
is
#if symbol-expression
statement sequence //from w w w . ja v a 2 s. co m
#elif symbol-expression
statement sequence
#elif symbol-expression
statement sequence
#elif symbol-expression
statement sequence
#elif symbol-expression
.
.
.
#endif
Example
Example,
#define AAA // ww w . j a va 2 s . com
#define RELEASE
using System;
class MainClass {
public static void Main() {
#if AAA
Console.WriteLine("Compiled for AAA version.");
#elif RELEASE
Console.WriteLine("Compiled for release.");
#else
Console.WriteLine("Compiled for internal testing.");
#endif
#if BBB && !RELEASE
Console.WriteLine("BBB version.");
#endif
Console.WriteLine("This is in all versions.");
}
}
The code above generates the following result.