Why does using const int SIZE = 5 for array size still result in error: variable-sized object may not be initialized?

Question

代码如下：

#include <stdio.h>

int main(void)
{
    const int SIZE = 5;
    int grades[SIZE]= {72, 65, 54, 39, 79};
    double sum = 0.0;
    int i;

    printf("My grades are: ");

    for(i = 0; i < SIZE; i++)
    {
        printf("%d\t", grades[i]);
    }
    printf("\n\n");

    printf("My grades average is: ");

    for(i = 0; i < SIZE; i++)
    {
        sum = sum + grades[i];
    }

    printf("%.2f\n\n", sum/SIZE);

    return 0;
}

当我尝试编译这段代码时，我得到：

average.c: In function 'main':
average.c:12:5: error: variable-sized object may not be initialized
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |     ^~~
average.c:12:24: warning: excess elements in array initializer
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |                        ^~
average.c:12:24: note: (near initialization for 'grades')
average.c:12:28: warning: excess elements in array initializer
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |                            ^~
average.c:12:28: note: (near initialization for 'grades')
average.c:12:32: warning: excess elements in array initializer
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |                                ^~
average.c:12:32: note: (near initialization for 'grades')
average.c:12:36: warning: excess elements in array initializer
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |                                    ^~
average.c:12:36: note: (near initialization for 'grades')
average.c:12:40: warning: excess elements in array initializer
   12 |     int grades[SIZE]= {72, 65, 54, 39, 79};
      |                                        ^~
average.c:12:40: note: (near initialization for 'grades')

我的理解是，声明和初始化 const int SIZE = 5 意味着 SIZE 是一个常量，没有可变大小。我已经看到了同一个问题的答案，但我不明白 const int SIZE 为什么不能使 SIZE 成为常量整数表达式。此外，我正在使用 const int SIZE = 5 学习 C 编程的课程，并且程序已正确编译和运行。

为什么 const int SIZE = 5 不正确，什么是正确的？

Answer 1

为什么不能用SIZE as #define SIZE ((uint8_t)5),这也是常量初始化，它是预处理器，所以它想要在运行时间环境中改变，

Why does using const int SIZE = 5 for array size still result in error: variable-sized object may not be initialized?

Why does using const int SIZE = 5 for array size still result in error: variable-sized object may not be initialized?

c

integer

expression

constants