C语言 在 C 中未声明（首次在此函数中使用）
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undeclared (first use in this function) in C
提问by DancingDylan
I know when you type this into search, there are a few similar "like" questions. Yet, all the ones I saw that weren't duplicate were from other sources besides C. Anyway, hope someone can help. I have a structure, declared in my header obviously.
我知道当你在搜索中输入这个时，会有一些类似的“喜欢”问题。然而，我看到的所有不是重复的都是来自除 C 之外的其他来源。无论如何，希望有人可以提供帮助。我有一个结构，显然在我的标题中声明。
struct Statistics //Super basic structure.
{
int mean;
int median;
int variance;
int grades;
int min;
int max;
};
All of these functions are working properly without the structure, that's why I'm trying to use one. For cleanliness, and just pure understanding. My error is this, I get the line 'stats' undeclared (first use in this function)when I call the function this structure is within.
所有这些功能在没有结构的情况下都能正常工作，这就是我尝试使用一个的原因。为了清洁，只是纯粹的理解。我的错误是这样的，当我调用这个结构所在的函数时，我得到了未声明的 'stats'行（第一次在这个函数中使用）。
This is where the error send me to:
这是错误将我发送到的地方：
display_grades_distribution(m, grades_scale,n, stats);
So my question is this, how could my compiler tell me that this structure is 'undeclared' and or that its the 'first use' in the program.
所以我的问题是，我的编译器怎么能告诉我这个结构是“未声明的”，或者它是程序中的“第一次使用”。
SNIPPET:
片段：
void display_grades_distribution(int m, int grades_scale[11][m], int n,
struct Statistics stats[])
{
printf("Mean = %22f\n", stats[0].mean);
printf("Variance = %18f\n", stats[0].variance);
printf("Median = %20f\n", stats[0].median);
printf("min = %16d\n", stats[0].min);
printf("max = %16d\n", stats[0].max);
}
int main(void)
{
//-------------------------------------------
for(m = 0, m < num_assignments; m++)
{
struct Statistics stats[5];
stats[m].mean = calculate_mean(grades,n);
stats[m].median = calculate_median(grades,n);
stats[m].variance = calculate_mean(grades,n);
stats[m].min = calculate_min(grades,n);
stats[m].max = calculate_max(grades,n);
}
//-------------------------------------------
**display_grades_distribution(m, grades_scale,n, stats);** //This causes the error.
}
回答by MikeCAT
struct Statistics stats[5];is local variable in the block used in forstatement, so it isn't visible after the forloop.
struct Statistics stats[5];是for语句中使用的块中的局部变量，因此在for循环后不可见。
Get it out of forstatement.
把它从for声明中取出来。
int main(void)
{
struct Statistics stats[5];
//-------------------------------------------
for(m = 0, m < num_assignments; m++)
{
stats[m].mean = calculate_mean(grades,n);
stats[m].median = calculate_median(grades,n);
stats[m].variance = calculate_mean(grades,n);
stats[m].min = calculate_min(grades,n);
stats[m].max = calculate_max(grades,n);
}
//-------------------------------------------
display_grades_distribution(m, grades_scale,n, stats);
}
