C语言 为什么主函数会出现“控制到达非空函数结束”的警告？
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Why a warning of "control reaches end of non-void function" for the main function?
提问by alittleboy
I run the following C codes and got a warning: control reaches end of non-void function
我运行以下 C 代码并收到警告：控制到达非空函数的结尾
int main(void) {}
Any suggestions?
有什么建议？
采纳答案by dreamcrash
Just put return 0in your main(). Your function main returns an int (int main(void)) therefore you should add a return in the end of it.
只需放入return 0您的main(). 您的函数 main 返回一个 int ( int main(void)) 因此您应该在它的末尾添加一个 return 。
Control reaches the end of a non-void function
控制到达非空函数的末尾
Problem: I received the following warning:
warning: control reaches end of non-void function
警告：控制到达非空函数的结尾
Solution: This warning is similar to the warning described in Return with no value. If control reaches the end of a function and no return is encountered, GCC assumes a return with no return value. However, for this, the function requires a return value. At the end of the function, add a return statement that returns a suitable return value, even if control never reaches there.
解决方案：此警告类似于无值返回中描述的警告。如果控制到达函数的末尾并且没有遇到返回，GCC 假定返回没有返回值。但是，为此，该函数需要一个返回值。在函数的末尾，添加返回合适的返回值的 return 语句，即使控制从未到达那里。
Solution:
解决方案：
int main(void)
{
my_strcpy(strB, strA);
puts(strB);
return 0;
}
回答by Pascal Cuoq
As an alternative to the obvious solution of adding a returnstatement to main(), you can use a C99 compiler (“gcc -std=c99” if you are using GCC).
作为向 中添加return语句的明显解决方案的替代方案main()，您可以使用 C99 编译器（如果您使用的是 GCC，则为“gcc -std=c99”）。
In C99 it is legal for main()not to have a returnstatement, and then the final }implicitly returns 0.
在 C99 中main()没有return声明是合法的，然后 final}隐式返回 0。
$ gcc -c -Wall t.c
t.c: In function ‘main':
t.c:20: warning: control reaches end of non-void function
$ gcc -c -Wall -std=c99 t.c
$
A note that purists would consider important: you should notfix the warning by declaring main()as returning type void.
一张纸条，纯粹主义者会认为重要的是：你应该不会通过声明固定预警main()为返回类型void。
回答by Kninnug
The main function has a return-type of int, as indicated in
main 函数的返回类型为 int，如
int main(void)
however your main function does not return anything, it closes after
但是你的主函数没有返回任何东西，它在之后关闭
puts(strB);
Add
添加
return 0;
after that and it will work.
在那之后，它将起作用。
