C+的main和c++有什么不同

What is the difference between main in a C program and in a C++ program?

C程序中的main和c++程序的区别是什么?

Other than

除了

return statement ( default 1 in C,`0 in C++)
返回语句(C默认为1,c++默认为0)

syntax:

语法:

int main() { /* … */ }
int main(int argc, char* argv[]) { /* … */ }
int main() ,  void main() ,etc ...

Mainly:

主要是:

difference between main in C Program & C++ program

C程序和c++程序中主程序的不同
Are there any differences between C++98, C++03 and C++0x according to the ISO standard? i.e program's entry point (program startup implementation), etc.

根据ISO标准，c++ 98、c++ 03和c++ 0x有什么不同吗?我。e程序的入口点(程序启动实现)等。

4 个解决方案

#1

In modern C, and modern C++:

在现代C和现代c++中:

main is always either int main() or int main(int, char*[]).
main总是int main()或int main(int, char*[])。
In C89, you have to return from main explicitly.
在C89中，必须显式地从main返回。
In C99 and C++, if you don't return explicitly, you implicitly return 0.
在C99和c++中，如果不显式返回，则隐式返回0。

[(I've checked the C99 standard now and edited this paragraph.)] For your second question, in C99 you must have precisely one of the two main functions. In C++ the standard says that a program is well-formed if it has a main function that returns int, and that every conforming implementation must accept the two listed versions as an entry point (for a "hosted program", e.g. not for the Linux kernel); see 3.6.1. [/edit] To the best of my knowledge, calling conventions are also not part of the standard.

对于你的第二个问题，在C99中，你必须有两个主要功能之一。在c++中，标准说如果一个程序有一个返回int的主函数，并且每个符合标准的实现都必须接受两个列出的版本作为入口点(对于“托管程序”，例如对于Linux内核);3.6.1见。[/编辑]就我所知，打电话习惯也不是标准的一部分。

I don't understand your question about memory, but do note that neither C99 nor C++03 have anything but a rudimentary memory model, whereas the new C++0x explicitly adds a memory model in order to enable well-defined concurrent and atomic operations.

我不理解您关于内存的问题，但是请注意，C99和c++ 03都没有基本的内存模型，而新的c++ 0x显式地添加了一个内存模型，以便启用定义良好的并发和原子操作。

#2

In C, as opposed to C++, main can be called recursively.

在C语言中，可以递归地调用main，而不是c++。

/* valid C */
#include <stdio.h>
int main(int argc, char **argv) {
  putchar(argc ? '.' : '\n');
  if (argc == 0) return 0;
  return main(argc - 1, NULL);
}

#3

C99 and C++ are put in line for the definition of main in hosted environments. There are two function interfaces that are allowed

C99和c++用于定义托管环境中的main。允许有两个函数接口

int main(void);
int main(int, char*[]);

Both languages allow the implicit return from main without return statement in which case a return value of EXIT_SUCCESS is returned to the caller.

两种语言都允许隐式返回main而不返回语句，在这种情况下，EXIT_SUCCESS的返回值返回给调用者。

#4

Edit: Is there any difference in program startup implementation is there any difference in c++98,C++03,C+++0x main ,etc.........

编辑:在程序启动实现上有什么不同在c+ 98、c+ 03、c++ +0x main等方面有什么不同……

Not in main. However, there is a huge difference in what happens before main is called in C versus C++. In C++, objects with static storage are typically initialized prior to entering main.

不是主要的。然而，在main在C和c++中调用之前发生的事情有很大的不同。在c++中，具有静态存储的对象通常在进入main之前进行初始化。

Note:
An implementation is allowed to perform dynamic initializations of static data in the midst of main, but it must do so prior to the first reference to that static data. I've never run across an implementation that takes advantage of this flexibility.

注意:允许实现在main中执行静态数据的动态初始化，但必须在第一次引用静态数据之前执行。我从未遇到过利用这种灵活性的实现。

#1