再次“要求非结构或联合的成员”

Question

sorry if I ask a question that has been done many times before, but i have found no solution.

I have this typedef struct

typedef struct                          
    {
    int matrix[row][col];
    }Position;

And i create a variable

Position park[weeks];

then i call it in a subroutine

void foo(struct Position *park[weeks]...)

and then

park[s].matrix[i][j]=car[k].id;

and i have the "request for etc etc" error, in this line above. What am I doing wrong? Sorry for my english.

Answer 1

Change

park[s].matrix[i][j]=car[k].id;

to

park[s]->matrix[i][j]=car[k].id;

You've declared parks as an array of pointers to Position , so you have to use the operator -> to access the matrix member.

Alternately, you could write

(*park[s]).matrix[i][j]=car[k].id;

but the -> operator is a little cleaner.

Answer 2

just delete the * in you foo. Then everything will be ok

void foo( Position *park[weeks]...)

==>

void foo(Position park[weeks]...)

Or

void foo(Position *park,...)

Like this:

typedef struct                          
{
    int matrix[2][2];
}Position;


void foo(Position *park)
{
    park[1].matrix[1][1]=5;
}

int main()
{
    Position park[2];
    foo (park);
    return 0;
}

I don't understand why typedef struct should put in main, however , if you have to , maybe you can put the function in the main too :

int main()
{
    typedef struct                          
    {
    int matrix[2][2];
    }Position;

    void foo(Position *park)
    {
    Position *park1 = (Position *)park;
    park1[1].matrix[1][1]=5;
    };
    Position park[2];
    foo (park);
    printf("%d\n",park[1].matrix[1][1]);
    return 0;
}