错误：可变大小的物体可能无法初始化 [英] Error: Variable-sized object may not be initialized

问题描述

 的#define L 1
＃定义M L + 1诠释主要（无效）{    INT N = L * M * 2;
    炭S [N] = {'1'，'2'};
    的printf（％D的sizeof（S））;    返回1;
}
 

为什么上面的code不能编译？ Eclipse的编译器说两件事情：

1. 的可变大小的物体可能无法初始化：的是，因为氮以M的定义和L在宏观还是因为我不能用的初始化数组类型改编[x]其中x是在任何情况下变量？


2. 的在数组初始化多余的元素的 - 什么意思

解决方案

  

因为我不能初始化型ARR数组[x]其中x是变量？

事实上，pre-C99，数组的大小必须是一个的恒前pression 的。在C99，这已经放宽用的变长数组的

（这是无关的宏）

  

在阵列initializer-是什么意思多余的元素？

解决的第一个问题，这应该走了。

#define L 1
#define M L+1

int main(void){

    int N=L*M*2;
    char s [N]={'1','2'};
    printf("%d", sizeof(s));

    return 1;   
}

Why does the above code cannot be compiled? The compiler of Eclipse says two things:

1. Variable-sized object may not be initialized: Is because the definition of N with M and L at the macro or is it because I can't initialize an array with type arr[x] where x is variable under any circumstances?
2. excess elements in array initializer- What does it mean?

解决方案

because I can't initialize an array with type arr[x] where x is variable?

Indeed, pre-C99, the array size must be a constant expression. In C99, this has been relaxed with variable-length arrays.

(This is is nothing to do with macros.)

excess elements in array initializer- What does it mean?

Fix the first problem, and this should go away.

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