Print a conversion table for (un)signed bytes

Question

Your task: Print or return a conversion table with every byte from 00 to ff's value as an unsigned integer, to its value as a signed one (using two's complement).

For example:

Formatting:

The output doesn't have to be padded to nicely line up like it does above (just a space in between would be fine)
The separators can be any two strings which can't be confused for the data or each other
Any base can be used (but if using binary, -1 would be -00000001, not 11111111)
Trailing (and/or leading) whitespace and separators are allowed
The output must be in the correct order
The output must be textual; returning arrays/lists/dictionaries is not allowed

Valid outputs:

(using ... to skip over some repetitive chunks)

Zero-padded hexadecimal:

00 00
01 01
...
7f 7f
80 -80
81 -7f
...
fe -02
ff -01

Binary with , and ; for separators:

0,0;1,1;10,10;11,11;...;01111111,01111111;10000000,-10000000;10000001,-01111111;...;11111110,-00000010,11111111,00000001

Negadecimal with custom separators:

0 The HORSE is a noble animal. 0

1 The HORSE is a noble animal. 1

...

287 The HORSE is a noble animal. 287

288 The HORSE is a noble animal. 1932

289 The HORSE is a noble animal. 1933

...

354 The HORSE is a noble animal. 18

355 The HORSE is a noble animal. 19

Good luck!

\$\begingroup\$ Does the output have to be in the order 0..255? \$\endgroup\$ – Neil Jan 15 at 14:30 — Neil, Jan 15 at 14:30
\$\begingroup\$ @Neil It needs to be in order, yes \$\endgroup\$ – Redwolf Programs Jan 15 at 14:33 — Redwolf Programs, Jan 15 at 14:33
\$\begingroup\$ Can there be leading separators? \$\endgroup\$ – att Jan 15 at 20:39 — att, Jan 15 at 20:39
\$\begingroup\$ @att Yes, that's fine \$\endgroup\$ – Redwolf Programs Jan 16 at 0:30 — Redwolf Programs, Jan 16 at 0:30
\$\begingroup\$ @JonathanAllan Fixed, thanks \$\endgroup\$ – Redwolf Programs Jan 16 at 18:40 — Redwolf Programs, Jan 16 at 18:40

Digital Trauma · Accepted Answer · 2021-01-15 17:20:02Z

9

Bash + coreutils, 30

(seq 0 127;seq -128 -1)|nl -v0

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answered Jan 15 at 17:20

Digital Trauma

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4

\$\begingroup\$ Nice use of nl! \$\endgroup\$ – user99151 Jan 16 at 1:11

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score 7 · Accepted Answer · 2021-01-17 01:35:20Z

7

C (gcc), 54 50 47 bytes

i;main(){for(;i<256;printf("%u,%hhd ",i++,i));}

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Explanation

i;                      // Static variable initialized to 0
main() {
    for(;i<256;         // While the variable is <= 255:
        printf("%u,%hhd ",i++,i));
                        //     Output the original, then the char-coerced
                        //     value. Increment after use.
}

C (gcc), 45 bytes

Non-portable, but 2 bytes shorter.

f(i){for(i=-1;i++<255;printf("%u,%hhd ",i));}

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edited Jan 17 at 1:35

answered Jan 15 at 13:58

user99151

3

\$\begingroup\$ 50 bytes using %hhd \$\endgroup\$ – EasyasPi Jan 15 at 14:17
2

\$\begingroup\$ You can use a static zero-initialized variable instead of argc (saves 2 bytes) \$\endgroup\$ – Artyer Jan 15 at 15:03
2

\$\begingroup\$ 47 bytes (includes @Artyer 's advice). \$\endgroup\$ – Arnauld Jan 15 at 15:46
1

\$\begingroup\$ 45 byte function \$\endgroup\$ – att Jan 16 at 5:06
1

\$\begingroup\$ @Artyer There's nothing wrong with arbitrary function names, but functions must be reusable. \$\endgroup\$ – Arnauld Jan 16 at 10:22

| Show 7 more comments

Adám · Accepted Answer · 2021-01-15 14:31:03Z

5

APL (Dyalog Extended), 18 bytes

Full program printing to stdout with ¯ as negative symbol. Requires 0-based indexing.

(⍳∘≢,⍪)…127,-128…1

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128…1 integers 128 through 1

- negate those

127, prepend 127

… fill integers from 0 until the first element of that (127)

(…) apply the tacit function:

,⍪ columnify and prepend [a column consisting of]…

⍳⍤≢ the ɩndices of the tally

edited Jan 15 at 14:31

answered Jan 15 at 14:25

Adám

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ovs · Accepted Answer · 2021-01-15 15:17:05Z

4

Python 2, 37 bytes

for i in range(256):print i,127-i^127

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edited Jan 15 at 15:17

answered Jan 15 at 14:56

ovs

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xigoi · Accepted Answer · 2021-01-16 19:09:36Z

4

Jelly, 11 10 bytes

⁹Ḷ_H%⁹żƊṢG

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-1 byte thanks to Jonathan Allan

Explanation

⁹Ḷ_H%⁹żƊṢG   Main niladic link
⁹             256
 Ḷ            [0..255]
  _           Subtract
   H          half (of 256) = 128 => [-128..127]
       Ɗ      (
    %           Modulo
     ⁹          256
      ż         Zip with the list at the beginning of this inner link
       Ɗ      )
         Ṣ    Sort
          G   Format as a grid

edited Jan 16 at 19:09

answered Jan 16 at 8:51

xigoi

1,8212 silver badges12 bronze badges

1

\$\begingroup\$ 10 bytes by using zip, ż to avoid €: ⁹Ḷ_H%⁹żƊṢG - TIO. \$\endgroup\$ – Jonathan Allan Jan 16 at 18:53
\$\begingroup\$ @JonathanAllan Thanks! I totally forgot Jelly had a zip dyad. \$\endgroup\$ – xigoi Jan 16 at 19:10

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Kevin Cruijssen · Accepted Answer · 2021-01-15 14:41:23Z

05AB1E, 11 10 bytes

₅ÝƵQÝÂ±«ø»

-1 byte thanks to @ovs.

Uses single spaces and newlines as delimiters for the output.

Try it online.

Explanation:

₅Ý        # Push a list in the range [0,255]
ƵQÝ       # Push a list in the range [0,127]
   Â      # Bifurcate it; short for Duplicate & Reverse copy
    ±     # Get the bitwise-NOT of each (n → -n-1)
     «    # Merge the top two lists together
ø         # Create all possible pairs of the [0..255] and [0..127,-128..-1] lists
 »        # Join each pair by spaces, and then each string by newlines
          # (after which the result is output implicitly)

See this 05AB1E tip of mine (section How to compress large integers?) to understand why ƵQ is 127.

@ovs Ah, of course! So obvious now that I see it, but I totally missed it. Thanks. :) — Kevin Cruijssen, Jan 15 at 14:42

Arnauld · Accepted Answer · 2021-01-15 15:18:24Z

JavaScript (ES6), 41 40 bytes

Saved 1 byte thanks to @ovs

Output format: 0,0 1,1 ... 255,-1.

f=n=>n>>8?'':[~~n,128+~n^127]+' '+f(-~n)

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Or maybe 39 bytes or even 38 bytes by abusing the loose output format. (But it's ugly.)

Commented

f =                  // f is a recursive function
n =>                 // taking a counter n, which is initially undefined
  n >> 8 ?           // if n = 256:
    ''               //   stop the recursion
  :                  // else:
    [                //   build an array consisting of:
      ~~n,           //     the unsigned value (coerced to a number because
                     //     it's undefined on the first iteration)
      128 + ~n ^ 127 //     the signed value, which is (127 - n) XOR 127
                     //                              = (128 + (-n - 1)) XOR 127
    ]                //   end of array
    + ' '            //   coerce the array to a string and append a space
    + f(-~n)         //   append the result of a recursive call with n + 1

\$\begingroup\$ 40 bytes with a slightly different formula. \$\endgroup\$ – ovs Jan 15 at 15:11 — ovs, Jan 15 at 15:11
\$\begingroup\$ @ovs Ah yes, nice one! \$\endgroup\$ – Arnauld Jan 15 at 15:19 — Arnauld, Jan 15 at 15:19
\$\begingroup\$ f=n=>n>>8?'':[~~n,n<<24>>24]+' '+f(-~n) \$\endgroup\$ – tsh Jan 16 at 12:27 — tsh, Jan 16 at 12:27

xigoi · Accepted Answer · 2021-01-16 01:07:55Z

3

Nim `-d:danger`, 33 32 bytes

for b in 0..255:b.echo' ',b.int8

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Nim, 40 39 bytes

for b in 0..255:b.echo' ',cast[int8](b)

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Probably doesn't work on big-endian architectures.

edited Jan 16 at 1:07

answered Jan 16 at 0:56

xigoi

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Razetime · Accepted Answer · 2021-01-16 10:12:29Z

3

Husk, 16 bytes

†szeŀ256Sṙohṡ128

Try it online!, Another method, Another method

Explanation

†szeŀ256Sṙohṡ128
            ṡ128 symmetric range of 128 [-128...128]
          oh     remove last element
        Sṙ       rotate 128 spaces
    ŀ256         range [0...255]
  ze             zip the two, creating pairs
†s               convert all the numbers to strings
                 (can also be mw)

edited Jan 16 at 10:12

answered Jan 15 at 15:47

Razetime

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Dominic van Essen · Accepted Answer · 2021-01-17 21:33:59Z

R, 37 bytes

for(i in 0:255)cat(i,i-(i>127)*256,T)

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Separator between converted numbers is " "; separator between each element of the list of conversions is " TRUE". List is appended with a trailing separator (as allowed by the challenge rules).
"TRUE" is a pre-defined variable in R that can be specified by a single character, T, and that has non-numeric output, so it's used as a convenient golfy separator here.

R, 38 bytes

cat(paste(0:255,c(0:127,-128:-1),'
'))

Try it online!, Another approach

Previous, slightly longer attempt, but with more-conventional separators (space & newline).

someone · Accepted Answer · 2021-01-19 02:37:12Z

3

Python 3, 47 41 bytes

-6 thanks to @EasyasPi

print([(127-i^127,i)for i in range(256)])

edited Jan 19 at 2:37

answered Jan 16 at 22:56

someone

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1

\$\begingroup\$ -6 using the 127-i^127 trick the other snek friends are using \$\endgroup\$ – EasyasPi Jan 16 at 23:13

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MarcMush · Accepted Answer · 2021-01-15 14:47:08Z

2

Julia 1.0, 31 bytes

Output format:

0 => 0
1 => 1...

println.(i=>i%Int8 for i=0:255)

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answered Jan 15 at 14:47

MarcMush

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Noodle9 · Accepted Answer · 2021-01-15 15:30:23Z

2

Python 2, ^{49 53} 51 bytes

Saved 2 bytes taking a peek at ovs's Python answer!!!
Added 8 bytes to fix a rule violation kindly pointed out by ovs.
Saved 2 bytes thanks to ovs!!!

f=lambda i=255:i*' 'and'%d '*2%(i,127-i^127)+f(i-1)

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edited Jan 15 at 15:30

answered Jan 15 at 14:57

Noodle9

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\$\begingroup\$ 51 bytes by shortening the base case and using the repetition in the formatting string. \$\endgroup\$ – ovs Jan 15 at 15:19
\$\begingroup\$ @ovs Nice one - thanks! :D \$\endgroup\$ – Noodle9 Jan 15 at 15:30

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Zaelin Goodman · Accepted Answer · 2021-01-15 15:38:58Z

2

PowerShell, 34 bytes

0..255|%{"$($_;($_-bxor128)-128)"}

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answered Jan 15 at 15:38

Zaelin Goodman

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hakr14 · Accepted Answer · 2021-01-15 19:26:35Z

2

Pyth, 17 16 bytes

V256++Nd-J127xNJ

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-1 byte thanks to FryAmTheEggman!

Python 3.8 translation:

for N in range(256):print(str(N)+" "+str((J:=127)-N^J))

edited Jan 15 at 19:26

answered Jan 15 at 16:43

hakr14

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\$\begingroup\$ Using J to reuse 127 should save a byte. Also, if not for the output restriction could save a byte by using B. \$\endgroup\$ – FryAmTheEggman Jan 15 at 19:03
\$\begingroup\$ @FryAmTheEggman thanks, I didn't realize JK assignment also returned the assigned value! \$\endgroup\$ – hakr14 Jan 15 at 19:27

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mazzy · Accepted Answer · 2021-01-15 20:21:27Z

2

PowerShell, 29 33 bytes

+4 bytes: fit to the task rules. Thanks @Zaelin Goodman

0..127+-128..-1|%{"$(($i++);$_)"}

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edited Jan 15 at 20:21

answered Jan 15 at 15:55

mazzy

5,7522 gold badges7 silver badges22 bronze badges

2

\$\begingroup\$ You have to also print the number being converted from; and array outputs are explicitly forbidden: The output must be textual; returning arrays/lists/dictionaries is not allowed \$\endgroup\$ – Zaelin Goodman Jan 15 at 18:53
\$\begingroup\$ Thanks, Zaelin. \$\endgroup\$ – mazzy Jan 15 at 20:51

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Eric Duminil · Accepted Answer · 2021-01-16 13:04:53Z

2

Ruby, 36 bytes

256.times{|i|puts [i,127-i^127]*' '}

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answered Jan 16 at 13:04

Eric Duminil

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Pedro Maimere · Accepted Answer · 2021-01-16 18:15:08Z

2

AWK, 48 45 bytes

Lowered to 45 bytes thanks to Dominic van Essen.

BEGIN{for(;i<256;i++)print +i,i<128?+i:i-256}

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Had to workaround the fact that bitwise functions in GNU AWK don't accept negative arguments. Anyway, this should work on any AWK implementation.

edited Jan 16 at 18:15

answered Jan 16 at 3:46

Pedro Maimere

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1

\$\begingroup\$ 45 bytes... \$\endgroup\$ – Dominic van Essen Jan 16 at 13:18
\$\begingroup\$ @DominicvanEssen - Clearly I was overthinking that last bit. \$\endgroup\$ – Pedro Maimere Jan 16 at 18:11
1

\$\begingroup\$ It seems One True Awk requires parenthesis around the conditional's test expression. Note also that no AWK I've tried requires the unary + operators on any of the print arguments. \$\endgroup\$ – Greg A. Woods Jan 18 at 22:26
\$\begingroup\$ Also, all versions of AWK I've tried will initialize variables to 1, not zero as required. \$\endgroup\$ – Greg A. Woods Jan 18 at 22:53
1

\$\begingroup\$ Ah, yes, I agree: The + will save one character of source v.s. initializing to zero. Note though that this trick of coercing the initial blank string to a zero will not work in older versions, including for example nawk from the Heirloom tools (which is arguably a bug in the older versions). This seems to have been fixed only since it was migrated to GitHub, probably in the changes dated 2018-08-22, so making it truly portable would still (and for a long time to come) require the explicit initialization to an integer. \$\endgroup\$ – Greg A. Woods Jan 19 at 0:12

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Michael Chatiskatzi · Accepted Answer · 2021-01-17 00:16:27Z

2

Scala, 46 45 bytes

()=>for(i<-0 to 255)print(s"$i,${i.toByte} ")

Output format: 0,0 1,1 2,2 ... 127,127 128,-128 129,-127 ... 253,-3 254,-2 255,-1 with , and for separators.

Try it online!

Edit: Due to conventions, the String Interpolator f was changed to s. Thanks to user!

37 bytes

... if ignoring the seperator rule.

()=>for(i<-0 to 255)print(i,i.toByte)

Output format: (0,0)(1,1)(2,2)(...)(127,127)(128,-128)(129,-127)(...)(253,-3)(254,-2)(255,-1) with , and )( for separators, but unfortunately also with a leading ( and trailing ).

Try it online!

edited Jan 17 at 0:16

answered Jan 15 at 20:39

Michael Chatiskatzi

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1

\$\begingroup\$ Nice! Btw, s is usually used instead of f. \$\endgroup\$ – user Jan 16 at 14:58

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AZTECCO · Accepted Answer · 2021-01-17 00:57:56Z

2

Haskell, 54 bytes

unlines[show x++' ':show(x-x`div`128*256)|x<-[0..255]]

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Sadly xor is not in prelude module.
Table is a string of pairs separated by newlines.

answered Jan 17 at 0:57

AZTECCO

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pinkfloydx33 · Accepted Answer · 2021-01-17 12:03:38Z

2

C#, 61 bytes

Not very creative, but I think the shortest this can get.

for(var i=0;i<256;)System.Console.Write(i+$",{(sbyte)i++};");

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This is a complete program thanks to C#9 and top-level statements. SharpLab

edited Jan 17 at 12:03

answered Jan 17 at 11:48

pinkfloydx33

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\$\begingroup\$ 45 bytes using Print \$\endgroup\$ – EasyasPi Jan 17 at 18:50
\$\begingroup\$ That's specifically C# interactive, post that as a seperate answer \$\endgroup\$ – pinkfloydx33 Jan 17 at 20:18

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ReedsShorts · Accepted Answer · 2021-01-21 15:51:15Z

2

FALSE, 37 bytes

0[$$$$256=~][128>[256-]?\.44,.10,1+]#

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answered Jan 21 at 15:51

ReedsShorts

1514 bronze badges

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movatica · Accepted Answer · 2021-01-21 17:20:19Z

2

Python 3, 38 bytes

for i in range(256):print(i,127-i^127)

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answered Jan 21 at 17:20

movatica

7151 silver badge6 bronze badges

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lorem.ipsum · Accepted Answer · 2021-01-22 10:48:49Z

2

Java, 58 chars

void f(){for(int i=0;i<256;out.println(i+" "+(byte)i++));}

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The byte data type is an 8-bit signed two's complement integer. It has a minimum value of -128 and a maximum value of 127 (inclusive).

edited Jan 22 at 10:48

answered Jan 18 at 23:25

lorem.ipsum

2157 bronze badges

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Galen Ivanov · Accepted Answer · 2021-01-15 14:25:20Z

1

Red, 45 bytes

repeat n 256[print[p: n - 1 p xor 128 - 128]]

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Uses @Arnauld's formula

answered Jan 15 at 14:25

Galen Ivanov

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Aiden4 · Accepted Answer · 2021-01-15 16:05:13Z

1

Rust, 45 bytes

||for i in 0..256{print!("{}:{}
",i,i as i8)}

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Note the newline literal, output format is

1:1
2:2
...

This prints the loop count as both an i32 and an i8. Note that as casts are not allowed to panic, so they may result in unexpected behavior on overflow.

answered Jan 15 at 16:05

Aiden4

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Kjetil S. · Accepted Answer · 2021-01-15 16:06:42Z

1

Perl 5, 32 bytes

say"$_ ",$_-2*($_&128)for 0..255

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edited Jan 15 at 16:06

answered Jan 15 at 15:54

Kjetil S.

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Neil · Accepted Answer · 2021-01-15 20:10:22Z

Charcoal, 17 bytes

ＩＥ⁺…⁰⊗℅@…±⊗℅@⁰⟦κι

Try it online! Link is to verbose version of code. Outputs in decimal with single and double newline as separators. Explanation:

   …                 Range from
    ⁰                Literal `0` to
       @            Literal string `@`
      ℅             ASCII code i.e. 64
     ⊗              Doubled i.e. 128
  ⁺                 Concatenated with
        …           Range from
            @       Literal string `@`
           ℅        ASCII code
          ⊗         Doubled
         ±          Negated
             ⁰      To literal `0`
 Ｅ                  Map over values
               κ    Current index
                ι   Current value
              ⟦     Wrap in list
Ｉ                   Cast to string
                    Implicitly print

Neil · Accepted Answer · 2021-01-15 20:29:52Z

Retina 0.8.2, 43 bytes


256$*_¶
_
$.` -$.'¶
128`-.+
$%`

Try it online! Uses space and newline as the delimiters, plus adds a variety of trailing spaces and newlines. Explanation:


256$*_¶

Insert 256 _s plus a newline which is used to balance out the number of characters after each _.

_
$.` -$.'¶

Replace each _ with a line giving the number of preceding and (with a minus sign) following characters.

128`-.+
$%`

Replace the first 128 minus numbers with the number that precedes it.

Xcali · Accepted Answer · 2021-01-16 04:33:43Z

1

Perl 5, 32 bytes

An alternative to @KjetilS's solution of the same length.

say$_,$",unpack c,chr for 0..255

Try it online!

answered Jan 16 at 4:33

Xcali

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Print a conversion table for (un)signed bytes

36 Answers 36

Bash + coreutils, 30

C (gcc), 54 50 47 bytes

Explanation

C (gcc), 45 bytes

APL (Dyalog Extended), 18 bytes

Python 2, 37 bytes

Jelly, 11 10 bytes

Explanation

05AB1E, 11 10 bytes

JavaScript (ES6), 41 40 bytes

Commented

Nim -d:danger, 33 32 bytes

Nim, 40 39 bytes

Husk, 16 bytes

Explanation

R, 37 bytes

R, 38 bytes

Python 3, 47 41 bytes

Julia 1.0, 31 bytes

Python 2, 49 53 51 bytes

PowerShell, 34 bytes

Pyth, 17 16 bytes

PowerShell, 29 33 bytes

Ruby, 36 bytes

AWK, 48 45 bytes

Scala, 46 45 bytes

37 bytes

Haskell, 54 bytes

C#, 61 bytes

FALSE, 37 bytes

Python 3, 38 bytes

Java, 58 chars

Red, 45 bytes

Rust, 45 bytes

Perl 5, 32 bytes

Charcoal, 17 bytes

Retina 0.8.2, 43 bytes

Perl 5, 32 bytes

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