C / C++ / MFC

1-Mar-06 23:04

Hi,
How to convert an array of Hex values to int in Visual C, is there any function for converting?

chaitu

Naveen1-Mar-06 23:09

Naveen

1-Mar-06 23:09

in what variable do u keep the hex values?????

if ur hex vaue is in some string u can use sscanf to convert it to integer..

nave

toxcct1-Mar-06 23:10

1-Mar-06 23:10

this doesn't mean anything to convert from hexadecimal to int...
hexadecimal IS an integer, but it only differs from the graphical representation...
if you have 32 apples, it is the same as having 0x20 apples...

what you certainly mean however is reading hexadecimal characters from a string (but that is important to know if it is a string or not) into ints... if so, sscanf() is done your you.

otherwise, give more details about what you really have, and what you really want...

cheers,

chaitanya221-Mar-06 23:25

1-Mar-06 23:25

It is an array BYTE data[212 Byte], i would like to chanage the hex values saved in the array to int values, as i should decode the polar coordinates from the Hex values saved in the data array.

toxcct1-Mar-06 23:28

1-Mar-06 23:28

if it is an array of bytes, then you don't need to "convert", you only need to copy, because as i said in my previous post, hexadecimal is only a representation of the binary in memory...

Cedric Moonen1-Mar-06 23:45

Cedric Moonen

1-Mar-06 23:45

v2.0 wrote:
if you have 32 apples, it is the same as having 0x20 apples...

It reminds me of another discussion[^]

Laugh | :laugh:

toxcct1-Mar-06 23:47

1-Mar-06 23:47

Cedric Moonen wrote:
It reminds me of another discussion[^]

exactly... Big Grin | :-D

i wanted to link the post, but couldn't find it...

the comparison still deserves '5' Rose | [Rose]

chaitanya222-Mar-06 1:41

2-Mar-06 1:41

Ya i got it guys....actually am alramed, i would like to convert the Hex to decimal value

Re: converting Hex to binary

Cedric Moonen2-Mar-06 2:18

Cedric Moonen

2-Mar-06 2:18

chaitanya22 wrote:
Ya i got it guys

Nope you didn't get it, otherwise you would not have asked again. What do you want to do EXACTLY ? And don't answer 'converting hex to decimal value' because this is totally nonsense ! Again, I will express it another way: it's like asking "I have 7 apples, I want to convert these apples in hexadecimal". Mmmmh, sounds, err, how to say....special, isn't ?
This is the same for your question.

So, formulate your question precisely. What do you want to do ? Convert a string representing a number ?

chaitanya222-Mar-06 2:08

Re: converting Hex to binary

2-Mar-06 2:08

I would like to convert Hex number i,e 40 or 0x0C or 0x04B to binary value or decimal value.

Maximilien2-Mar-06 2:26

Maximilien

2-Mar-06 2:26

why not do :

int i = 0x30; // or whatever hex number you have...

Maximilien Lincourt
Your Head A Splode - Strong Bad

Roger Stoltz2-Mar-06 2:15

Roger Stoltz

2-Mar-06 2:15

The function I think you're looking for is strtol() declared in <stdlib.h>.
strtol() takes a string and converts it into a long.
You'll find more info about it here[^].

Hope this helps
--
Roger

It's supposed to be hard, otherwise anybody could do it!

chaitanya222-Mar-06 2:21

2-Mar-06 2:21

would that function convert Hex number to binary value?
for eg:0x65=1100101,, i would like to ahve so...

Cedric Moonen2-Mar-06 2:58

Cedric Moonen

2-Mar-06 2:58

Even with the explanation of the apples you still don't get it. In other tearms: hex numbers and decimal numbers doesn't exist (it's a bad use of the language). Instead you should say hexadecimal REPRESENTATION or binary REPRESENTATION of a number.

Let's take an example:

int BinValue = 0b1100101;   // In binary
int HexValue = 0x65;   // In hexadecimal
int DecValue = 101;   // In decimal

In this example, all three numbers are exactly the same and if you compare them, the result will be true.

Hope it is clear now.

Function with default argument

Konrad Windszus2-Mar-06 3:59

Konrad Windszus

2-Mar-06 3:59

Do you mean a string in hexadecimal format? You can do such a conversion with strtol. If you set the last parameter to 0 it does even automatically detect the number base depending on the first characters, e.g. if you have a string like 0xFF it will be converted to the integer value 255.
Here is an example code:

<br />
const char* szNumber = "0x1234";<br />
char* pHelp;<br />
<br />
int nNumber = strtol(szNumber, &pHelp, 0);

Regards
Konrad

vikramlinux1-Mar-06 23:00

vikramlinux

1-Mar-06 23:00

Hi
friends
I have a structure declared like this

typedef unsigned char byte;
typedef struct date
{
short year;
byte month;
byte day;
}date_t;

and a function

void function(date_t t)
{
}

here I want to set some default value to this argument "date_t t' say NULL.

void function(date_t t=NULL)
{
}

How I can do that?

toxcct1-Mar-06 23:02

1-Mar-06 23:02

void function(date_t t = {0, 0, 0}) {
}

vikramlinux1-Mar-06 23:10

vikramlinux

1-Mar-06 23:10

It dosent work...

toxcct1-Mar-06 23:12

1-Mar-06 23:12

getting any error from the compiler ?

Stephen Hewitt1-Mar-06 23:12

Stephen Hewitt

1-Mar-06 23:12

Add some constructors:

struct date_t
{
     date_t()
     {
         // Set default date here...
     }
     date_t(short y, byte m, byte d): year(y), month(m), day(d)
     {}
     short year;
     byte month;
     byte day;
};

Now you can use it as follows:

date_t d1 = date_t(2006, 1, 1);
date_t d2 = date_t(); // Default;
void function(date_t t = date_t())
{
}

Steve

vikramlinux1-Mar-06 23:13

vikramlinux

1-Mar-06 23:13

well my limitation is I can not modify the date_t structure code.

toxcct1-Mar-06 23:16

1-Mar-06 23:16

so why not creating two overloads of the function ? one with no parameters, the other getting a date_t ?

moreover, even without changing the date_t structure, using function(date_t t = date_t()) { } should work if the structure don't define any constructor (the compiler defines one by default).

Lim Bio Liong2-Mar-06 0:15

Lim Bio Liong

2-Mar-06 0:15

Hello v2.0,

Is the fact that the default constructor sets all struct field values to 0 a C++ Standard or is it compiler-dependent ?

Thanks, v2.0,
Bio.

toxcct2-Mar-06 0:19