Convert to double value

[ashishbhatt12]

Hi all,

i have a problem in the value which stored in memory location.i want to convert it into the double value.

Suppose, i have the value
int k = 2;

when I write it on the memory location like, it is like ..

40 00 00 00 00 00 00 00

But when i retrieve it from memory location then it gives me reverse like...

00 00 00 00 00 00 00 40

So, I want to convert it in to Double value.

Little much Strange question, but I am facing this problem.

Plz reply me, if u got solution .

thanks in advance.

Ashish

[gpraghuram]

Hi all,

i have a problem in the value which stored in memory location.i want to convert it into the double value.

Suppose, i have the value
int k = 2;

when I write it on the memory location like, it is like ..

40 00 00 00 00 00 00 00

But when i retrieve it from memory location then it gives me reverse like...

00 00 00 00 00 00 00 40

So, I want to convert it in to Double value.

Little much Strange question, but I am facing this problem.

Plz reply me, if u got solution .

thanks in advance.

Ashish

How are u retrieving it from memory...usually this wont happen .

Raghuram

[ashishbhatt12]

I have used this code to check the value stored on memory and so I found the output like as explained.


double x = 2;
unsigned char *str;
str = (unsigned char *)malloc(sizeof(unsigned char *));
str = (unsigned char *)&x;

CString st, str1;
str1 = "";
for(int i = 0; i < 8; i++)
{
st.Format(CString("%.2X "), *(str++));
str1.Append(st);
}
AfxMessageBox(str1);



here the output like as below....

00 00 00 00 00 00 00 40 in messagebox.

[gpraghuram]

I have used this code to check the value stored on memory and so I found the output like as explained.


double x = 2;
unsigned char *str;
str = (unsigned char *)malloc(sizeof(unsigned char *));
str = (unsigned char *)&x;

CString st, str1;
str1 = "";
for(int i = 0; i < 8; i++)
{
st.Format(CString("%.2X "), *(str++));
str1.Append(st);
}
AfxMessageBox(str1);



here the output like as below....

00 00 00 00 00 00 00 40 in messagebox.

Hi,
You cant read double values using this approach because the double and float are stored using the IEEE format and you can get an idea about it if u search in the net.
Also there are some minor issues in the code
You need not allocate memory for str variable and as you use %x as format specifier i dont think you can get the actual value as it gets converted to hex(i am not sure abt this)

Raghuram

[weaknessforcats]

Let's go back to int k = 2;

In binary that's:

0000 0000 0000 0000 0000 0000 0000 0010
<-byte 3-> <-byte 2-> <-byte 1-> <-byte 0->

If you are big-endian (like Unix/Linux) the bytes are written:

Address:
0 byte 3
1 byte 2
2 byte 1
3 byte 0

If you are little-endian (like Windows) the bytes are written:
Address:
0 byte 0
1 byte 1
2 byte 2
3 byte 3

Hence the bit pattern in memory will be different.