main() 在 C 和 C++ 中应该返回什么? [英] What should main() return in C and C++?

问题描述

在 C 和 C++ 中定义 main() 函数的正确(最有效)方法是什么 - int main() 或 void main() — 为什么?那么论据呢?如果 int main() 那么 return 1 还是 return 0?

What is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments? If int main() then return 1 or return 0?

这个问题有很多重复，包括:

• 什么是 C 的 的有效签名main() 函数?
• main() 函数的返回类型
• void main() 和 int main()?
• main() 在 C++ 中的签名
• 什么是main()? — 对于 C++，确实是一个很好的答案.
• C 中main() 函数的样式
• main() 方法的返回类型C
• int main() vs void main() in C

• What are the valid signatures for C's main() function?
• The return type of main() function
• Difference between void main() and int main()?
• main()'s signature in C++
• What is the proper declaration of main()? — For C++, with a very good answer indeed.
• Styles of main() functions in C
• Return type of main() method in C
• int main() vs void main() in C

相关:

• C++ — int main(int argc, char **argv)
• C++ — int main(int argc, char *argv[])
• 是 char *envp[] 作为 main() 可移植的第三个参数?
• 必须是 int main() 函数在所有编译器中都返回一个值?
• 为什么C和C++中main()函数的类型留给用户定义?
• 为什么要编译 int main(){}?一个>
• C++ 中 main() 的法律定义14?

• C++ — int main(int argc, char **argv)
• C++ — int main(int argc, char *argv[])
• Is char *envp[] as a third argument to main() portable?
• Must the int main() function return a value in all compilers?
• Why is the type of the main() function in C and C++ left to the user to define?
• Why does int main(){} compile?
• Legal definitions of main() in C++14?

推荐答案

main 的返回值指示程序如何退出.正常退出由 main 的 0 返回值表示.非零返回表示异常退出，但没有关于如何解释非零代码的标准.正如其他人所指出的，void main() 是 C++ 标准禁止的，不应使用.有效的 C++ main 签名是:

The return value for main indicates how the program exited. Normal exit is represented by a 0 return value from main. Abnormal exit is signaled by a non-zero return, but there is no standard for how non-zero codes are interpreted. As noted by others, void main() is prohibited by the C++ standard and should not be used. The valid C++ main signatures are:

int main()

和

int main(int argc, char* argv[])

相当于

int main(int argc, char** argv)

还值得注意的是，在 C++ 中，int main() 可以不带返回语句，此时它默认返回 0.这对于 C99 程序也是如此.return 0; 是否应该省略还有待商榷.有效的 C 程序主签名的范围要大得多.

It is also worth noting that in C++, int main() can be left without a return-statement, at which point it defaults to returning 0. This is also true with a C99 program. Whether return 0; should be omitted or not is open to debate. The range of valid C program main signatures is much greater.

效率不是 main 函数的问题.根据C++标准，它只能进入和离开一次(标记程序的开始和终止).对于 C，允许重新输入 main()，但应避免.

Efficiency is not an issue with the main function. It can only be entered and left once (marking the program's start and termination) according to the C++ standard. For C, re-entering main() is allowed, but should be avoided.

这篇关于main() 在 C 和 C++ 中应该返回什么?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！