main

问题 This question already has answers here : Is main() overloaded in C++? (6 answers) Closed 2 years ago . Since C+++ allows function overloading, can we overload main() ? For example, int main(const std::string &) { return 0; } int main(int argc, char *argv[]) { return main("calling overloaded main"); } gcc-4.3.4 doesn't compile this, and gives these errors: (see at ideone) prog.cpp:4: error: first argument of ‘int main(const std::string&)’ should be ‘int’ prog.cpp:4: error: ‘int main(const std:

问题 I'd like to use a main() function in my GAE code (note: the code below is just a minimal demonstration for a much larger program, hence the need for a main() ). If I use the following code, it performs as expected: import webapp2 class GetHandler(webapp2.RequestHandler): def get(self): self.response.headers['Content-Type'] = 'text/plain' self.response.write('in GET') class SetHandler(webapp2.RequestHandler): def get(self): self.response.headers['Content-Type'] = 'text/plain' self.response

问题 I have seen a main() function in some JavaScript files I have come across. Is it the same main function as you use in other languages such as C#, C++?? If you put a main function in your JS file, is that where the code starts executing? Or is it just another name used for a function? I have searched the web but didn't find anything useful regarding this matter. 回答1: No, main is not the same in JavaScript as in C languages. It's just another function, but the original programmer is probably

问题 I'm writing a program that contains multiple packages in it. Each package has its own main program that I want all to launch simultaneously when the .jar is executed by an interpreter. This seems like a fairly simple question, but when I looked around, it seems that people are using ants (which I've never used before) and other methods. Is there a simpler way in Eclipse to compile a .jar with multiple launch configurations, better yet, is there a way to hard code it in? If the best way to

问题 I'm writing a program that contains multiple packages in it. Each package has its own main program that I want all to launch simultaneously when the .jar is executed by an interpreter. This seems like a fairly simple question, but when I looked around, it seems that people are using ants (which I've never used before) and other methods. Is there a simpler way in Eclipse to compile a .jar with multiple launch configurations, better yet, is there a way to hard code it in? If the best way to

问题 It will look like int main(int argc, char *argv[]); . My questions are: 1 How many array items can I add in argv[] ? 2 What is MAX size of every char * ? 回答1: You can try: $ getconf ARG_MAX 2180000 http://pubs.opengroup.org/onlinepubs/007904975/basedefs/limits.h.html ARG_MAX is maximum length of argument to the exec functions including environment data. That is, there is no individual limit on the number of arguments or argument's length. Only the limit on total size required to store all the

问题 I've been learning C programming in a self-taught fashion for some weeks, and there are some questions that I have concerning the main() function. All functions must be declared in their function prototype, and later on, in their defintion. Why don't we have to declare the main() function in a prototype first? Why do we have to use int main() instead of void main() ? What does return 0 exactly do in the main() function? What would happen if I wrote a program ending the main() function with

问题 Is main() (or Main()) in C, C++, Java or C#, a user-defined function or a built-in function? 回答1: It's a user-defined function that is necessary for a program to execute. When you go to run your program in the compiled language, the main function is what is executed. For instance, in Java, if you have a function of the signature public static void main(String ... args) in a class then that class can be executed, as the JVM will execute the contents of that main method. Example in Java: public

问题 This question already has answers here : What should main() return in C and C++? (17 answers) Closed 6 months ago . In C++, 3.6.1 Main function (3.6.1/5) A return statement in main has the effect of leaving the main function (destroying any objects with automatic storage duration) and calling exit with the return value as the argument. If control reaches the end of main without encountering a return statement, the effect is that of executing return 0; Can I do the following in C99 without

问题 If I create an Objective-C iOS application in Xcode, a file named main.m is generated. The contents of the file look something like this: main.m #import <UIKit/UIKit.h> #import "AppDelegate.h" int main(int argc, char * argv[]) { @autoreleasepool { return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); } } And this is where an Objective-C iOS application begins its life. Importantly, if I want to subclass UIApplication (for whatever reason), then here is where I go