Simple hex formatting question

[Gil Pius]

I have an int value which I know is between 0 and 255. I'd like to
obtain a String containing two hex digits from it. I've looked at the
Integer class and while it has a toHexString() method that method can
produce as few as one digit. So if my int was 0 through 15 I'd get
hex '0' thruough 'F'. I could get the length of the string and
"prepend" a second zero in such cases, but I can't help but wonder if
there's a simpler way to do this in Java that I'm missing. Any help
would be greatly appreciated.

Thanks,

Gil

[xarax]

Re: Simple hex formatting question

gilpius@iname.c om (Gil Pius) wrote in message news:<3d815ea8. 0308270218.7280 bccc@posting.go ogle.com>...[color=blue]
> I have an int value which I know is between 0 and 255. I'd like to
> obtain a String containing two hex digits from it. I've looked at the
> Integer class and while it has a toHexString() method that method can
> produce as few as one digit. So if my int was 0 through 15 I'd get
> hex '0' thruough 'F'. I could get the length of the string and
> "prepend" a second zero in such cases, but I can't help but wonder if
> there's a simpler way to do this in Java that I'm missing. Any help
> would be greatly appreciated.
>
> Thanks,
>
> Gil[/color]

Cross posted to comp.lang.java. programmer where it belongs.

You could just have a static final String[] with 256
elements ranging from "00", "01", ... , "fe", "ff" (i.e.,
the sequence of hexadecimal representations ). Then simply
index the array with (0xff & val) to select the String.

[Phil...]

Re: Simple hex formatting question

don't you mean to have just "=" and not "+=" on the first line?

"Douwe" <douwe@parkserv er.net> wrote in message
news:df9b3384.0 308270919.3b883 1a3@posting.goo gle.com...[color=blue]
> xarax@email.com (xarax) wrote in message[/color]
news:<306d5c8f. 0308270511.e15f b8b@posting.goo gle.com>...[color=blue][color=green]
> > gilpius@iname.c om (Gil Pius) wrote in message[/color][/color]
news:<3d815ea8. 0308270218.7280 bccc@posting.go ogle.com>...[color=blue][color=green][color=darkred]
> > > I have an int value which I know is between 0 and 255. I'd like to
> > > obtain a String containing two hex digits from it. I've looked at the
> > > Integer class and while it has a toHexString() method that method can
> > > produce as few as one digit. So if my int was 0 through 15 I'd get
> > > hex '0' thruough 'F'. I could get the length of the string and
> > > "prepend" a second zero in such cases, but I can't help but wonder if
> > > there's a simpler way to do this in Java that I'm missing. Any help
> > > would be greatly appreciated.
> > >
> > > Thanks,
> > >
> > > Gil[/color]
> >
> > Cross posted to comp.lang.java. programmer where it belongs.
> >
> > You could just have a static final String[] with 256
> > elements ranging from "00", "01", ... , "fe", "ff" (i.e.,
> > the sequence of hexadecimal representations ). Then simply
> > index the array with (0xff & val) to select the String.[/color]
>
> Although your version is really quick I think the next one looks nicer:
>
> static final String TXT_HEX = "0123456789ABCD EF";
> public String toHexString(int val) {
> String result;
> result += TXT_HEX[(val>>4) & 0xF];
> result += TXT_HEX[(val) & 0xF];
> return result
> }[/color]

[Roedy Green]

Re: Simple hex formatting question

On 27 Aug 2003 06:11:04 -0700, xarax@email.com (xarax) wrote or quoted
:
[color=blue][color=green]
>> I have an int value which I know is between 0 and 255. I'd like to
>> obtain a String containing two hex digits from it.[/color][/color]

see http://mindprod.com/jgloss/hex.html

--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.

[Douwe]

Re: Simple hex formatting question

"Phil..." <rynes@ieee.org > wrote in message news:<gJ93b.276 013$o%2.125768@ sccrnsc02>...[color=blue]
> don't you mean to have just "=" and not "+=" on the first line?
>
> "Douwe" <douwe@parkserv er.net> wrote in message
> news:df9b3384.0 308270919.3b883 1a3@posting.goo gle.com...[color=green]
> > xarax@email.com (xarax) wrote in message[/color]
> news:<306d5c8f. 0308270511.e15f b8b@posting.goo gle.com>...[color=green][color=darkred]
> > > gilpius@iname.c om (Gil Pius) wrote in message[/color][/color]
> news:<3d815ea8. 0308270218.7280 bccc@posting.go ogle.com>...[color=green][color=darkred]
> > > > I have an int value which I know is between 0 and 255. I'd like to
> > > > obtain a String containing two hex digits from it. I've looked at the
> > > > Integer class and while it has a toHexString() method that method can
> > > > produce as few as one digit. So if my int was 0 through 15 I'd get
> > > > hex '0' thruough 'F'. I could get the length of the string and
> > > > "prepend" a second zero in such cases, but I can't help but wonder if
> > > > there's a simpler way to do this in Java that I'm missing. Any help
> > > > would be greatly appreciated.
> > > >
> > > > Thanks,
> > > >
> > > > Gil
> > >
> > > Cross posted to comp.lang.java. programmer where it belongs.
> > >
> > > You could just have a static final String[] with 256
> > > elements ranging from "00", "01", ... , "fe", "ff" (i.e.,
> > > the sequence of hexadecimal representations ). Then simply
> > > index the array with (0xff & val) to select the String.[/color]
> >
> > Although your version is really quick I think the next one looks nicer:
> >
> > static final String TXT_HEX = "0123456789ABCD EF";
> > public String toHexString(int val) {
> > String result;
> > result += TXT_HEX[(val>>4) & 0xF];
> > result += TXT_HEX[(val) & 0xF];
> > return result
> > }[/color][/color]


oops :)

[Jon A. Cruz]

Re: Simple hex formatting question

xarax wrote:[color=blue]
> gilpius@iname.c om (Gil Pius) wrote in message news:<3d815ea8. 0308270218.7280 bccc@posting.go ogle.com>...
>[color=green]
>>I have an int value which I know is between 0 and 255. I'd like to
>>obtain a String containing two hex digits from it. I've looked at the[/color][/color]

[color=blue]
> Cross posted to comp.lang.java. programmer where it belongs.
>
> You could just have a static final String[] with 256
> elements ranging from "00", "01", ... , "fe", "ff" (i.e.,
> the sequence of hexadecimal representations ). Then simply
> index the array with (0xff & val) to select the String.[/color]


Or...

String s = Integer.toHexSt ring( 0x100 | (0x0ff & i) ).substring(1);