如何在函数中编写多维数组？ 初学者的C编程

Question

I'm first year student and I do C programming. Don't be so mean to me, please.

Could you show how to use and write multi-dimensional arrays in functions?

I have researched the arrays and function arg input.

I have read that the first dimension is not that important to the compiler. It checks the second and further dimensions in an array, so you have to specify it even in the function to make it work.

I tried different combinations for arrays to make it work but didn't find a solution.

There is a little piece of my code:

int size=5,location_x=10,location_y=10,s=NULL,l_x, l_y, status=2;

int stage_3(float[][int],int [],int [],int []);

int main()
{
float location[l_x][l_y];
int x[size], y[size], z[size];

if(!stage_3(location[l_x][l_y],x[size],y[size],z[size]))
    return 0;
}

int stage_3(float location[][int l_y],int x[size],int y[size],int wt[size])
{
  return 0;
}

13|error: expected expression before 'int'

13|error: expected ';', ',' or ')' before 'int'

I have idea that the problem are those [][]. They are not constants. The program makes them as variables that you could choose by scanf as you wish in accessible range for more flexibility.

Answer 1

This prototype cannot work:

int stage_3(float[][int],int [],int [],int []);

You need to give the actual size of the second dimension of the first array. If that size is not a compile-time constant, then your best option is probably to use a variable-length array. Here's a good way to do that:

int stage_3(int l_y, float location[][l_y],int x[],int y[],int z[]);

Of course, the function definition must be altered to match, and if you use an additional argument to express the variable dimension, as above, then you must include the extra argument in your function call as well.

VLAs were new in C99; some compilers still need to be instructed to use C99 mode to compile code that uses them.