Toggle line numbers 1 #define Square (x) ( (x)* (x)) 2 Now if you write Square (foo) it will expand as ( (foo)* (foo)). How to avoid this. Making statements based on opinion; back them up with references or personal experience. How to check whether a string contains a substring in JavaScript? Some of your comments gave me an idea to sort out the answer. For version (2), the number of arguments must be the same as the number of parameters in macro definition. The content you requested has been removed. I tested it on both VC and GCC with all pedantic options I found out without any warning messages. is there any way to eliminate this. You must log in or register to reply here. //theprogramtoassignvaluestostruct1.xandstruct1.yasfollows: structname.x=user_x;//ThisiswhereIrunintotrouble structname.y=user_y;//Iknowthecodeisnotcorrect,butthisisjustto. Can you show code for both to clarify what you want to achieve and what your restrictions are ? Are defenders behind an arrow slit attackable? This can also be achieved in a standard manner using __VA_OPT__, such as fprintf (stderr, format __VA_OPT__(, ) __VA_ARGS__). Asking for help, clarification, or responding to other answers. since TRACE(Hello) is used in another macro am using as TRACE(("Hello")) and more over , can use printf function. FavoriteColor variable, and return the value of 55. This is what Microsoft did using COM. Sign in to post your reply or Sign up for a free account. - All these variables are numeric variables Here is what I am trying to do: - I would like to label some of the existing variables, rename some of the existing variables and create new variables - I have been trying to get a handle on using macros and use it for the above tasks but keep running into errors does not have parentheses after itself, it is not replaced at all. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content. Converting an Access database to a web-based format. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The string "name" has 5 words, so my dataset one should have 5 variables starting with word1 till word5 containing the corresponding words. What's the exact exception the compiler returns? However, when I try to append '_TBL' as a suffix, rather than prefix, the step fails thinking that the '_TBL' is part of the macro variable name. Formula/Macro to convert email address(es) copied from Outlook to only first and last names, VBA Check for duplicates and modify variable in different ways. They do not (or rather, may not) exist in the final executable. The sequence is terminated by the matching ) token, skipping intervening matched pairs of left and right parentheses. It doesn't look as though this is possible, from the lack of information I can find on the web so far. by assert. The ## operator in macros expands out both sides (VAR and Pos) and then concatenates the results together. ?i=i+1loop until i = 15Also how would i do this with objects.say i had a series of labels named label1, labe2, label3ect to call these througha "label + i.tostring + .text" script alsoCatch my drift.is this possible?Thanks! The values of these macros (except for __FILE__ and __LINE__) remain constant throughout the translation unit. How do I tell if this single climbing rope is still safe for use? C Linux GCC C++ #include <iostream> using namespace std; #define getName (VariableName) # VariableName int print ( int num) { std::cout<< getName (num) <<": {"<< num <<"}"<<std::endl; } int main () { int mynum; std::cout<<"enter number->"<<std::endl ; std::cin>> mynum; print (mynum); } What I have tried: i got output: However, Excel (and other Office products) support collections that include most if not all objects that the application supports. So there is no way if I want to do, say: No, unlike some other languages VB(A) doesn't support the creation of variable names from the contents of other variables. Attempts to redefine or undefine these macros result in undefined behavior. @Jens: if the invocation of TRACE has double parentheses as in the question, this is OK. We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. What are the criteria for a protest to be a strong incentivizing factor for policy change in China? The following additional macro names may be predefined by the implementations. You are using an out of date browser. rev2022.12.9.43105. Thanks for the prompt response. In C, there's a # directive, also called 'Stringizing Operator', which does this magic. Essentially, strings are just ASCII characters, and C file containing variable names can be thought of in the same way. How do I make the first letter of a string uppercase in JavaScript? #define TEMP_OBJ (string) MyType obj_ <some magic here (string); Drop the semicolon after the macro definition. This page has been accessed 716,595 times. It seams that you will have to read some things about Collections. The #undef directive undefines the identifier, that is cancels previous definition of the identifier by #define directive. This page was last modified on 14 October 2022, at 08:48. You can't get the value of var1 by typing var + i.tostring. 3 #define TRACE (arg1,.) So something like. You should a Collection to deal with this. Are C1 to C10 variable names or cell references? Are the S&P 500 and Dow Jones Industrial Average securities? Does integrating PDOS give total charge of a system? Following are the variable types defined in the header time.h . macros are expanded during the preprocess time, so the macro would take the variable name as parameter on the above code. In function-like macros, a # operator before an identifier in the replacement-list runs the identifier through parameter replacement and encloses the result in quotes, effectively creating a string literal. Visit Microsoft Q&A to post new questions. When would I give a checkpoint to my D&D party that they can return to if they die? Follow these easy steps to disable AdBlock, Follow these easy steps to disable AdBlock Plus, Follow these easy steps to disable uBlock Origin, Follow these easy steps to disable uBlock. Append a string to a macro variable for name of output data set. It gives an errorI've tried many times but the syntax is off.Does anyone know the correct syntax for this? cout<<"Enterthexvalueyouwouldliketoassignthestructure:"; cout<<"Entertheyvalueyouwouldliketoassingthestructure:"; //So,iftheusertypes"struct1"(withoutthequotes),Iwouldlike. To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page. This forum has migrated to Microsoft Q&A. They are part of the C language starting with C99. Version (2) of the #define directive defines a simple function-like macro. The standard defines a set of preprocessor macros corresponding to C++ language features introduced in C++11 or later. Ryan Michael Kay in Didact. #define F() f(0 __VA_OPT__(,) __VA_ARGS__), #define G(X, ) f(0, X __VA_OPT__(,) __VA_ARGS__), #define SDEF(sname, ) S sname __VA_OPT__(= { __VA_ARGS__ }), If the result begins with a sequence matching the syntax of, This can also be achieved in a standard manner using, #define FUNCTION(name, a) int fun_##name() { return a;}, #define OUTPUT(a) std::cout << "output: " #a << '\n', // Using a macro in the definition of a later macro, https://en.cppreference.com/mwiki/index.php?title=cpp/preprocessor/replace&oldid=144339, denotes the version of C++ standard that is being used, expands to value, expands to the name of the current file, as a character string literal, can be changed by the, expands to the source file line number, an integer constant, can be changed by the, expands to the date of translation, a character string literal of the form, expands to the time of translation, a character string literal of the form, implementation-defined value, if present, typically used to indicate C conformance, expands to an integer constant of the form. For example if you have source data in NAME, VALUE pairs then you can use PROC TRANSPOSE to convert the data into variable using the value of NAME as the name of the variable and VALUE as the value for the variable. Can you uses a string variable as the name of a new variable? Hi all, I have a request to create variables in a dataset depends on the number of words a particular string has. If you want to print a string, you need to keep track of a string as a variable. I'm having trouble in converting the string "Hello" into a variable name. You can access the controls by name from within the parent either by name or by index: Me .Controls (<control name>) If this we are talking about normal variables, then I'd be boring and strongly suggest using a collection. However, I'm not sure how to convert the variable name 'data1' to a string, or . How do I read / convert an InputStream into a String in Java? Instead, this would work (assuming you have three labels named Label1, Label2, and Label3): Were sorry. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. How do I iterate over the words of a string? (since C++23) If the result of concatenation is not a valid token, the behavior is undefined. With parentheses (hello) will not be a variable. By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use. Find centralized, trusted content and collaborate around the technologies you use most. The preprocessor supports text macro replacement. So no, what you're wanting to do is not possible in C++*. The output file is the same as the input with 'TBL_' added as a name prefix. (since C++20) Example Run this code Dim FavoriteNumber as Integer. FavoriteNumber = 55. For the issue with controls, in VB.Net 2003 I was getting an error trying to access the control collection by control name. #include <fmt/core.h> #include <numeric> #include <iostream> #include <vector> std::string format_variable_size (const char . So I'm retaining it. Connect and share knowledge within a single location that is structured and easy to search. return 0; } I'm having trouble in converting the string "Hello" into a variable name. The string is written in a simple template language: characters are usually copied literally into the function's output, but format specifiers, which start with a % character, indicate the location and method to translate a piece of data (such as a number) to characters. Use a string name entry in the struct and have the user enter that and locate the matching struct, creating one with that name if there isn't one. Function-like text macro replacement is also supported. What do you mean by "can use printf function" ? For a better experience, please enable JavaScript in your browser before proceeding. The way you would use a map is as follows: Apr 2 '08
char* arg1; int main (void) { int a=4; TRACE ( ("Hello",a)); // convert "Hello" to a valid char variable name. The function which outputs the data will be passed various different arrays so hardcoding the name of the heading is not possible - ideally I'd like to convert the variable name to some string and then output that string followed by the contents of the vector array. This determination does not consider the replacement of universal character names in translation phase 3. In this process, a continuous response variable, known as a dependent variable, is measured under experimental conditions identified. Mar 31 '08
another problem is the inner parenthesis (). A translation unit that uses any part of the standard library may not #define or #undef names lexically identical to: except that likely and unlikely may be defined as function-like macros. The following macro names are predefined in every translation unit. Search for .net collection tutorials on google. JavaScript is disabled. (since C++20). Only tokens that form a valid token together may be pasted: identifiers that form a longer identifier, digits that form a number, or operators + and = that form a +=. ; kd - Keeps only numeric values; d - Remove numerical values from String. Received a 'behavior reminder' from manager. For. To learn more, see our tips on writing great answers. How do I convert a String to an int in Java? #. A contains a string, "A Tale of Two Cities", and B contains another string, "The Forty Rules . #. Library Variables. How do I replace all occurrences of a string in JavaScript? //nowthatstruct1hasbeenassignedvalues: cout<<"Xhasbeenassignedthevalueof"<
); or BOOST_FOREACH(std::pair p, m)), the comma is interpreted as macro argument separator, causing a compilation failure due to argument count mismatch. They are intended as a simple and portable way to detect the presence of said features. You can help keep this site running by allowing ads on MrExcel.com. If you are new to the term collection, it is essentially the same as an associative array in some other languages. It does not work this way. #. Why does the USA not have a constitutional court? Version (4) of the #define directive defines a function-like macro with variable number of arguments, but no regular arguments. When a macro parameter is used with a leading '#', the preprocessor replaces it with the literal text of the actual argument, converted to a string Basically # directive converts its argument in a string. Version (3) of the #define directive defines a function-like macro with variable number of arguments. Object-like macros replace every occurrence of defined identifier with replacement-list. Function-like macros replace each occurrence of defined identifier with replacement-list, additionally taking a number of arguments, which then replace corresponding occurrences of any of the parameters in the replacement-list. Returns a pointer to a string which represents the day and time of the structure timeptr. What do you mean 'act like a variable'? How is the merkle root verified if the mempools may be different? cout<<"Xhasbeenassignedthevalueof"<