Array of void pointers in C

Question

I would like to create arrays of void pointers.

# include <stdio.h>
# include <stdlib.h>
# include <unistd.h>

int main(){

void * A[3];
void * D[3];
void * F[2];
void * G[4];
void * H[4];
void * J[3];
void * K[5];
void * L[4];
void * M[5];


A={D, H, K};
D ={A, G, H};
F ={K, L};
G={D, H, J, M};
H={A, G, L, M};
J={G, L, M};
K={A, F, H, L, M};
L={F, J, K, M};
M={G, H, J, K, L};
return 0;
}

The problem is the code won't compile it says: "expected expression before { token"

What is wrong? I am using these pointers because their value doesn't matter I just want them to point to each other. For example M has to point to G, H, J, K and L.

Thank you very much for any help or advice,

Jesus Ramos · Accepted Answer · 2011-08-31 19:01:17Z

6

You have to do it on the same line if you want to use that notation. In your case you would have to do

A[0] = D;
A[1] = H;
A[2] = K;

and so on because you need to add void * to symbols that havent been resolved at that point yet.

answered Aug 31, 2011 at 19:01

Jesus Ramos

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Hogan · Accepted Answer · 2011-08-31 19:03:22Z

4

This is the way C works.

I believe you want code that looks like this:

A[0] = D;
A[1] = H;
A[2] = K;

or code that looks like this:

void * A[3]={D,H,K};

answered Aug 31, 2011 at 19:03

Hogan

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Comments

David Heffernan · Accepted Answer · 2011-08-31 19:01:47Z

2

You can't use array initializers as assignments. You'll need to do the assignments element wise:

A[0] = D;
A[1] = H;
A[2] = K;

answered Aug 31, 2011 at 19:01

David Heffernan

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1 Comment

Blagovest Buyukliev Over a year ago

It would be helpful to point out that although D, H and K are arrays, they automatically decay to a pointer when used on the right side of an assignment.

Shahbaz · Accepted Answer · 2011-08-31 19:37:51Z

2

Arrays are not allowed on the left side of an assignment except when declared, and array initializers could be used only during declarations as well.

So you would have to write for example:

A[0] = D;
A[1] = H;
A[2] = K;

edited Aug 31, 2011 at 19:37

Shahbaz

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answered Aug 31, 2011 at 19:01

Blagovest Buyukliev

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