初始化指针数组到结构数组

Question

I'm trying to find a logical way to initialize a large number of arrays containing a large number of initialized structs so that a function can select a struct from the table and read its values. I wrote some very simple test code, but I know I am doing something wrong along the way.

The contents of "struct_test.h"

int my_test_var = 0;

typedef struct
{
    int a;
    int b;
}my_struct;

const my_struct tbl1[] = 
{
    {0x01,0x02},
    {0x03,0x04},
};

const my_struct tbl2[] = 
{
    {0x05,0x06},
    {0x07,0x08},
};

const my_struct *struct_tbl[] =
{
    tbl1,
    tbl2,
};

The contents of "struct_test.c"

#include "struct_test.h"

int main(void)
{
    if(struct_tbl[0][0].a == 0x01) 
        my_test_var = 0x01;

    return 0;
}

I would expect to read the value of my_test_var as 0x01, but it returns as 0. I think something might be wrong with how I am writing struct_tbl, but I am not sure.

I'd appreciate any help. Sorry if this is a very simple question, I'm just an EE trying to learn to write better code!

Edit: Declared int my_test_var externally, still same result.

Edit2: Updated code to include complete files. The weird result I get is that when I compile and run on my 64-bit Linux machine, I get the expected result. However, when I run on my 16-bit micro (Freescale Star12) my_test_var returns as zero. Through a watch window I can see each element of struct_tbl points to NULL rather than tbl1 and tbl2.

Answer 1

if(struct_tbl[0][0].a == 0x01) 
    int my_test_var = 0x01;

Get rid of the int keyword. This is declaring a (nested) variable which is in scope in the if statement only. After the if statement ends, the variable disappears.

if (struct_tbl[0][0].a == 0x01) 
    my_test_var = 0x01;