解法: https://stackoverflow.com/questions/2335888/how-to-compare-strings-in-c-conditional-preprocessor-directives 解法1,換成流水號: #defineUSER_JACK1#defineUSER_QUEEN2#defineUSER USER_JACK#if USER == USER_JACK#defineUSER_VS USER_QUEEN#elifUSER==USER_QUEEN#defineUSER_VS USER_JACK#endif...
The following conditional preprocessor directives are supported in AL.#if - Specifies the beginning of a conditional clause. The #endif clause ends it. Compiles the code between the directives if the specified symbol being checked is defined. #else - Specifies a compound conditional clause. If ...
As in C and C++, any numerical value that equals zero is considered "False", and any non-zero value is "True". Ignoring Condition VariablesIf you do not specify a variable's value, then any preprocessor statement that includes that variable is skipped and simply ignored. This is the ...
GDL preprocessor conditional directives define conditional constructs. Each conditional construct begins with the#Ifdefdirective and is terminated by the#Endifdirective. In between, the#Elseifdefdirective might appear zero, one, or more times. The optional#Elsedirective must appear between the last#Elsei...
C C language Preprocessor The preprocessor supports conditional compilation of parts of source file. This behavior is controlled by #if, #else, #elif, #ifdef, #ifndef, #elifdef, #elifndef(since C23), and #endif directives. Syntax#if expression #ifdef identifier #ifndef identifier #elif ...
The preprocessor supports conditional compilation of parts of source file. This behavior is controlled by#if,#else,#elif,#ifdef,#ifndef,#elifdef,#elifndef(since C++23), and#endifdirectives. Syntax #ifexpression #ifdefidentifier #ifndefidentifier ...
In the preceding example,Bisn't evaluated andC()isn't called ifAis null. However, if the chained member access is interrupted, for example by parentheses as in(A?.B).C(), short-circuiting doesn't happen. The following examples demonstrate the usage of the?.and?[]operators: ...
That is, if one operation in a chain of conditional member or element access operations returns null, the rest of the chain doesn't execute. In the following example, B isn't evaluated if A evaluates to null and C isn't evaluated if A or B evaluates to null: C# Copy A?.B?.Do(...
I would also like that TS supports conditional compilation, but more in the C++/C# way too. My main use is for assertions. @mhegazysaid "Pre-processor directives (i.e.#ifdefs) are not desirable." I took him at his word. As far as your example, I am a bit lost on how the follo...
In config: {loader:'webpack-preprocessor-loader',options:{directives:{dev:process.env.NODE_ENV==="development",},},}, In code: // #!devconsole.log("DEBUG ONLY"); During the compilation, if the value ofdevisfalse, the exact line of code under the directive will be omitted, and vice...