2d Array Help

[sleuth]

Hi,

I've almost worked through my problem previously posted, now I'm having trouble with a 2d array.

char table[10][50];

table[1234567]['A']='Test';

I get a segmentation fault for that. The number is an id number, I have no need to have it positioned in that spot of the array.

So how can I do this, What I need to do with it once it works is get to the A through the id number.

table[1234567]['A']

Something like that.

Thanks,
Tony

 

[tmoody]

Tony,

Here is some code I pasted in from my 2D array. The first 1D array is an index into the 2D array. If we have a match in the loop, I print a manufacturing location. It's probably not what you are looking for, or even the best solution but it's what I have. I had to paste in fake manufacturing locations due to trade secrets. In this case the bios info would be like "P12345678" with the "P" representing a manufacturing location. With that in mind the loop would print our "PLocation"

Tim

unsigned char *ManChar;
ManChar = (bios + 0x281); /* pointer to a string in memory */

const char manLookup[20]={0x41,0x42,0x43,0x44,0x46,0x47,0x48,0x4A,0x4B,0x4C,0x4D,0x4E,0x50,0x51,0x52,0x53,0x54,0x55,0x58,0x00 };

const char manString[20][25]={{"ALocation"},{"BLocation"},{"CLocation"},{"DLocation"},{"ELocation"},{"FLocation"}, {"GLocation"},{"HLocation"},{"ILocation"},{"JLocation"},{"KLocation"},{"LLocation"},{"MLocation"},{"NLocation"},{"OLocation"},{"PLocation"},{"QLocation"},{"RLocation"},{"SLocation"} };


for( i=0; i<sizeof(manLookup); i++)
{
if (manLookup == *ManChar)
{
printf(&quot;\tManufactured At : %s\n&quot;,manString);
found = 1;
break;
}
}

 

[sleuth]

I'm still having trouble,

I'm always thinking in terms of how I would do it in perl, this is where I think the larger part of the problem is.

Would you advise me on how you would access the value of a Letter, from a ten digit number.

Or just explain why,

const char manString[20][25]={{&quot;ALocation&quot;},{&quot;BLocation&quot;},{&quot;CLocation&quot;},{&quot;DLocation&quot;},{&quot;ELocation&quot;},{&quot;FLocation&quot;}, {&quot;GLocation&quot;},{&quot;HLocation&quot;},{&quot;ILocation&quot;},{&quot;JLocation&quot;},{&quot;KLocation&quot;},{&quot;LLocation&quot;},{&quot;MLocation&quot;},{&quot;NLocation&quot;},{&quot;OLocation&quot;},{&quot;PLocation&quot;},{&quot;QLocation&quot;},{&quot;RLocation&quot;},{&quot;SLocation&quot;} };

Doesn't let me access it using manString{&quot;ALocation&quot;} or manString[&quot;ALocation&quot;].

That's perl thinking right there, &quot;Always looking for the shortcut&quot;.

Good thing you didn't reveal any trade secrets, I wouldn't want you to have to kill me, hehe.

Thanks,
Tony

 

[Pappy1942]

Hi,
What you need is not a 2d array. In C a string is already an array of char's.

A structure containing an array of char's and a char would work.

Below is an example.
// Start Code
#include <stdio.h>
#include <string.h>

struct table
{
char idnum[8];
char idlet;

};

int main()
{
struct table list[50];

strcpy(list[0].idnum, &quot;1234567&quot;
list[0].idlet = 'A';
return 0;
}

// End Code
The above gives a list of 50 ID numbers and letters.
Hope this helps.
Pappy
You learn something everyday.

 

[Lim]

What you have done:
char table[10][50]; created 2d array of chars.
This array can hold 10 string with 49 chars in each.

By typing this:
table[1234567]['A']='Test';
you are trying to access char in 1234567 string (but you have only 10), on position (int)A. C will treat 'A' as in integer and it will be something around 100.
Anyway just read C book you are so far from C basic that I don't see the point to go any further.

 

[sleuth]

Ok Folks, Thank you, I'm going to try what you said Pappy, Thanks for the explanation Lim.

I suppose I'm just be getting creative now.

Tony

 

[tmoody]

Tony, I think Pappy set you straight. Use a structure. To access ALocation in my example would be
manString[0], or if you want SLocation it is
manString[18]. I search the 1D array for the first letter of my string. I use the location in the 1D array as an index into the 2D array. Like I said, it ain't the best way to do what I am doing. If I had to re-do it, I would use a structure. Tim