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Oct 24th, 2009

Problem in Pointers!!

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Hi all!
Please somebody explain me how this snippet is working!!

C Syntax (Toggle Plain Text)
main()
{
float a 4.379;
char*p;
int i;
p=(char*)&a;
for(i=1;i<=3;i++)
printf("%02X",(unsigned char)p[i]);
}
main()
{
float a 4.379;
char*p;
int i;
p=(char*)&a;
for(i=1;i<=3;i++)
printf("%02X",(unsigned char)p[i]);
}

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its.avinash

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Oct 24th, 2009

Re: Problem in Pointers!!

Click to Expand / Collapse Quote originally posted by its.avinash ...

Hi all!
Please somebody explain me how this snippet is working!!
C Syntax (Toggle Plain Text)
main()
{
float a 4.379;
char*p;
int i;
p=(char*)&a;
for(i=1;i<=3;i++)
printf("%02X",(unsigned char)p[i]);
}
main() { float a 4.379; char*p; int i; p=(char*)&a; for(i=1;i<=3;i++) printf("%02X",(unsigned char)p[i]); }

The code simply assigns the address of "a" to the character pointer "p" and then proceeds to check the value of the four bytes at address p[0], p[1],p[2], and p[3]...

Last edited by gerard4143; Oct 24th, 2009 at 8:20 pm.

gerard4143

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Oct 24th, 2009

Re: Problem in Pointers!!

Well it looks like that's what it's supposed to do.
It should print the hex representation of the floating point number 4.379.

But I don't see how it will compile and it will only print 3 of the 4 hex bytes.

SVR

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Oct 25th, 2009

Re: Problem in Pointers!!

function to display the floating number
the float numbers are stored in sign exponent mantissa fashion
furthur reading
http://steve.hollasch.net/cgindex/coding/ieeefloat.html

void test()
{
float f=5.25;
char *p=(char *)&f;
int i;
for(i = 3; i >= 0; i-- )
printf("%x\n",p[i]);
}
refer the attachment for out put on my system .

Attached Files

New Microsoft Excel Worksheet.zip (50.1 KB, 28 views)

Gaiety

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