# Challenge

You have one string of input bytes, output the last byte in it.

# Rules

Your submission may be a program or function outputting the last byte in the input which

• is either a string, stdin or command-line arguments, and
• is non-empty.

I was trying to solve this with brainfuck, however all languages are allowed to participate. This is .

# Examples

"?" -> "?"
"29845812674" -> "4"

• Welcome, I changed your question to fit our format more properly (note this is what the sandbox is for, usually). However in its current state the challenge is very easy (also in bf), so not sure about that. – ბიმო Mar 17 at 19:11
• I vote against closing; it may be trivial, but that doesn't make it offtopic – MilkyWay90 Mar 17 at 22:30
• @MillyWay I think most of the close votes were before the extensive edit by ბიმო – Sanchises Mar 18 at 6:47
• @ბიმო We have a consensus not to edit off-topic questions to make them on-topic which I think would have applied here. – Laikoni Mar 18 at 7:19
• What kind of string? Is it guaranteed to be ASCII only? Or should we handle UTF-8 (and how?) for example? – FireCubez Mar 18 at 18:28

## Batch, 24 bytes

@set s=%1
@echo %s:~-1%


Takes input as a command-line argument. Note that arguments can't include special characters or spaces, but you can fake arguments with spaces in this case by preceding it with a ", which results in a single argument that begins with ", however there is no easy solution for arguments that include special characters. Batch can't easily read "all of stdin". To read up to but not including the first newline itself would however be a byte shorter:

@set/ps=
@echo %s:~-1%


Edit: A version that handles arbitrary characters in a (quoted) argument for 92 bytes:

@set s="%~1"
@set "s=%s:~-2,1%
@if "%s%"=="" (echo ^")else for %%s in ("%s%")do @echo %%~s


Explanation: The first line makes a copy of the argument in a variable and ensures that it is quoted. The second argument then takes the second last character (because the quote is now the last character). However, if that was also a quote then this results in an empty variable, so we need to special-case that and output a (quoted) quote. Otherwise, we still need to quote the character in case it is a special character as echoing "%s%" will echo the quotes and echoing %s% will actually interpret special characters, so the variable needs to be quoted to allow it to be parsed but then immediately unquoted so it can be printed. This is achieved using the for command. 86 bytes to read up to but not including the first newline from stdin while supporting special characters:

@set/ps=
@set "s=%s:~-1%
@if "%s%"=="" (echo ^")else for %%s in ("%s%")do @echo %%~s


# Scratch 3.0, scratchblocks3 syntax

## As a function, 61 bytes

define l


## As a full program, 68 bytes

when gf clicked


Try both online

# Befunge-98, 5 bytes

~2j@,


Try it online!

### Explanation:

~           Take input
2j         Skip next two instructions
~           Repeat until EOF, where it reflects
@,       Print the last character and exit


# C# (Visual C# Interactive Compiler), 11 bytes

x=>x.Last()


Try it online!

• you can use a function :P – ASCII-only Mar 18 at 0:47
• OK - Ill update my answer :) – dana Mar 18 at 1:21
• uhm why is testcase in STDIN not footer – ASCII-only Mar 18 at 1:38
• Wow - It's been a while. Thanks for pointing that out ;) – dana Mar 18 at 1:39
• That's not how I understand it. I understand that it should print the last non-empty character. We need to ask OP. – Ven Mar 18 at 17:33

# Japt, 1 byte

Ì


Try it online!

-1 byte thanks to Quintec!

• 1 byte – Quintec Mar 18 at 2:00

# Bash, 13 bytes

echo ${1: -1}  string is passed as argument. Try it online ! # APL+WIN, 4 bytes ¯1↑⎕  Prompt for input string and select last byte. # Emotion, 5 bytes 😶👉😃😨👿  Explanation 😶 Push a copy of the first stack value. 👉 Push the length of the first stack value interpreted as a string. 😃 Push literal 1 😨 Push the difference of the second and first stack values. 👿 Push the character of the second stack value at the index of the top stack value.  Try it online! • in your readme, 1. i think "to emoji" should be "from emoji" 2. if it should be "from emoji" then emotinomicon and emojicode are a thing already – ASCII-only Mar 18 at 10:24 • Actually what you're looking at is output from a compiler, which can also be accessed via the online interface. – Quantum64 Mar 18 at 14:45 • Isn't each emoji more than one byte? I'd think they'd be two bytes at least. – Kyle Delaney Mar 18 at 20:18 • Emotion uses a custom code page. See quantum64.github.io/EmotionBuilds/1.1.0//… – JPeroutek Mar 18 at 20:53 # Whitespace, 54 bytes [N S S N _Create_Label_LOOP][S S S N _Push_0][S N S _Duplicate_0][T N T S _Read_STDIN_as_character][T T T _Retrieve_input][S N S _Duplicate][S S S T S T S N _Push_10][T S S T _Subtract][N T S S N _If_0_Jump_to_Label_PRINT][N S N N _Jump_to_Label_LOOP][N S S S N _Create_Label_PRINT][S N N _Discard_top][T N S S _Print_as_character]  Letters S (space), T (tab), and N (new-line) added as highlighting only. [..._some_action] added as explanation only. Since Whitespace can only take input as integer or character, we must add a trailing character to indicate we're done with the input-string after reading it character by character, for which I've used a newline. Try it online (with raw spaces, tabs and new-lines only). Example run: input = A2# Command Explanation Stack Heap STDIN STDOUT STDERR NSSN Create Label_LOOP [] SSSN Push 0 [0] SNS Duplicate top (0) [0,0] TNTS Read STDIN as character [0] {0:65} A TTT Retrieve at heap address (0) [65] {0:65} SNS Duplicate top (65) [65,65] {0:65} SSSTSTSN Push 10 [65,65,10] {0:65} TSST Subtract top two (65-10) [65,55] {0:65} NTSSN If 0: Jump to Label_PRINT [65] {0:65} NSNN Jump to Label_LOOP [65] {0:65} SSSN Push 0 [65,0] SNS Duplicate top (0) [65,0,0] TNTS Read STDIN as character [65,0] {0:50} 2 TTT Retrieve at heap address (0) [65,50] {0:50} SNS Duplicate top (50) [65,50,50] {0:50} SSSTSTSN Push 10 [65,50,50,10] {0:50} TSST Subtract top two (50-10) [65,50,40] {0:50} NTSSN If 0: Jump to Label_PRINT [65,50] {0:50} NSNN Jump to Label_LOOP [65,50] {0:50} SSSN Push 0 [65,50,0] SNS Duplicate top (0) [65,50,0,0] TNTS Read STDIN as character [65,50,0] {0:35} # TTT Retrieve at heap address (0) [65,50,35] {0:35} SNS Duplicate top (35) [65,50,35,35] {0:35} SSSTSTSN Push 10 [65,50,35,35,10] {0:35} TSST Subtract top two (35-10) [65,50,35,25] {0:35} NTSSN If 0: Jump to Label_PRINT [65,50,35] {0:35} NSNN Jump to Label_LOOP [65,50,35] {0:35} SSSN Push 0 [65,50,35,0] SNS Duplicate top (0) [65,50,35,0,0] TNTS Read STDIN as character [65,50,35,0] {0:10} \n TTT Retrieve at heap address (0) [65,50,35,10] {0:10} SNS Duplicate top (10) [65,50,35,10,10] {0:10} SSSTSTSN Push 10 [65,50,35,10,10,10] {0:10} TSST Subtract top two (10-10) [65,50,35,10,0] {0:10} NTSSN If 0: Jump to Label_PRINT [65,50,35,10] {0:10} NSSSN Create Label_PRINT [65,50,35,10] {0:10} SNN Discard top [65,50,35] {0:10} TNSS Print as character to STDOUT [65,50] {0:10} # {0:10} error  Stops with the error: Exit not defined. # Turing Machine Code, 72 42 bytes Assumes an input with no empty cells (spaces). Thanks to ASCII-only for saving 30 bytes. 0 * * r 1 1 * * l 2 1 _ _ l halt 2 * _ r 0  Old version in 72 bytes: 0 * * r 0 0 _ * l 1 1 * * l 2 2 * _ l 2 2 _ _ r 3 3 _ _ r 3 3 * * * halt  • 0 * * r 1/1 * * l 2/1 _ _ l halt/2 * _ r 0? – ASCII-only Mar 18 at 0:22 • oi pls reply :|| – ASCII-only Mar 18 at 0:35 • wouldn't work in what way? I've tested it online – ASCII-only Mar 18 at 1:46 • @ASCII-only It turns out you're correct, and I was simply misinterpreting the way your program actually worked. I think it's different enough that you can post it as a different answer if you want to. – SuperJedi224 Mar 18 at 2:42 • Well, this is a simple challenge, don't think it needs more than one answer in any language :P – ASCII-only Mar 18 at 3:22 # Japt -h, 1 byte U  Run it online # Runic Enchantments, 5 bytes i1Z%@  Try it online! Note that input handling in Runic has implicit conversion and breaks on spaces. \ denotes a literal space (works on newlines too) and numerical values are never strings. # Binary-Encoded Golfical, 17 bytes Hex-dump of binary encoded file: 00 60 02 1b 1a 08 01 14 16 14 24 1d 0a 01 14 18 14  Original image: Magnified 45x with colors labeled: The original image (the tiny one, not the magnified version) can be run using the interpreter normally. The binary encoded file (of which a hexdump is included above) can either be transpiled back to the image version with the Encoder program included in the github repo, or run directly using the interpreter by adding the -x flag. # Chip-z, 41 bytes S >vvvvvv~t ABCDEFG |Zz||Zz zbcZzfg a de  Try it online! Assumes that either the byte string does not contain zero (\0), or that it designates the end of the string. Alternate solution (45 bytes): azABZbczCDZdezEFZfgzG S-^^----^^----^^----^~t  Try it online! # Forth (gforth), 17 bytes : f 1- + 1 type ;  Try it online! ### Explanation Adds string-length - 1 to the string address and then prints a string of length 1 starting at that address. ### Code Explanation : f \ start a new word definition 1- \ subtract 1 from string length + \ add result to string address 1 type \ print string of length 1 starting at the new address ; \ end word definition  # R, 35 bytes Takes the input, splits it in to a list, outputs the last element of the list. tail(strsplit(scan(,''),'')[[1]],1)  Try it online! # Japt -h, 1 byte Can handle input as a string, integer or character/digit array. s  Try it # Retina, 10 9 bytes (.|¶)*$1


Try it online!

# INTERCAL, 270 bytes

DO,1<-#1PLEASECOMEFROM(2)DOWRITEIN,1DO.1<-,1SUB#1DO.5<-#1$!1~#256'DO.2<-.3DO(1)NEXTPLEASE.2<-'"!3~#1'$!3~#16'"$"!3~#4'$!3~#64'"'$'"!3~#2'$!3~#32'"$"!3~#8'$!3~#128'"'DO(1010)NEXTPLEASE,1SUB#1<-.3PLEASEREADOUT,1DOGIVEUP(1)DO(1002)NEXTDO(1009)NEXTDO.3<-.3~#255(2)DOFORGET#1


Try it online!

Writing this was... interesting. I was thinking I might want to use INTERCAL to INTERCALate, but I'm a bit less sure now.

Ungolfed and commented:

        DO ,1<-#1             PLEASE NOTE We want the input array to only have space for one element, so it will only take one at a time
DO COME FROM (2)
DO WRITE IN ,1        PLEASE NOTE If this is the first byte of the input, it'll write its value... but if not, it'll write the
previous value minus its value mod 256.
DO .1<-,1SUB#1
DO .5<-#1$!1~#256' PLEASE NOTE .5 is 3 if the input is 256, 2 otherwise DO .2<-.3 DO (1) NEXT PLEASE NOTE If we're here, we've found the end of the input. Now, we need to print it back out... C-INTERCAL's array I/O, in order to determine what it will actually print, subtracts the value it's going to print from the previous one (still mod 256, and with the previous value defaulting to 0), and then reads the bits of the byte backwards. So in order to go from the value we want to display to the value we need to feed into READ OUT, we reverse the bits and then subtract from 256. The nightmarish expression on the following line reverses the bits the best way I could think to: individually select each one out and then mingle them all back together. It may be possible to emulate the method used in cesspool.c, by using mingle and unary AND as a substitute for binary AND where we can't afford for select to rearrange it, but it might end up longer... DO .2 <- '"'.3~#1'$'.3~#16'"$"'.3~#4'$'.3~#64'"'$'"'.3~#2'$'.3~#32'"$"'.3~#8'$'.3~#128'"'

DO (1010) NEXT        PLEASE NOTE .1 already has 256 in it, which is very convenient for when you need to subtract .2 from 256.

DO ,1SUB#1 <- .3      PLEASE NOTE If we just read .3 out, we'd get a Roman numeral instead of the correct output.

DO GIVE UP            PLEASE NOTE End of program.

(1) DO (1002) NEXT        PLEASE NOTE that that line in syslib does 1001 next, which pops .5 entries off the next-stack and returns
control flow to the last one, such that if .5 is 2 flow will come back here, but if it's 3 then it'll go back
to the line that nexted to this one.

Here we add .1 and .2 into .3, then truncate it to a byte before looping back (while managing the next-stack
responsibly so the program doesn't disappear into the black lagoon for any input over 79 (?) bytes)

DO (1009) NEXT
DO .3<-.3~#255
(2) DO FORGET #1


# LiveScript, 8 bytes

(.[*-1])


Explanation:

(.[*-1])
(.[*-1]) # "BIOP": operator section à la Haskell
.[   ]  # Index into the implicit argument
*-1   # In [], "*" refers to the length


## F#, 14 8 bytes

Seq.last


-6 bytes thanks to aloisdg.

Strings are treated as sequences in F#, so you can use the Seq.last function to get the last character in it.

• Seq.last is a function. You can remove the let s= – aloisdg Mar 19 at 8:19

last


Functions are allowed, right?

Also with IO (18 bytes):

main=interact\$last

• The same answer was already posted, though we do allow duplicate answers as far as I know. – Laikoni Mar 24 at 21:22

# C (gcc), 31 bytes

f(int*s){gets(s),printf("%s");}


Try it online!

• O_o how does this even work – ASCII-only Mar 31 at 10:52
• I have no idea, it just works. – Natural Number Guy Mar 31 at 14:07

# C, 3635 34 bytes

x(char*v){printf(v+strlen(v)-1);}


Really simple stuff here. Nothing to ungolf either.

Saved one byte thanks to ceilingcat
Fixed the answer and saved another byte thanks to ASCII-only

• invalid, you need to change to printf – ASCII-only Mar 31 at 10:55

# Python 3, 16 bytes

This is a pretty basic answer, but I think that it is the lowest Python 3 can go...

x=lambda a:a[-1]


TIO

• you don't need the x= here – ASCII-only Mar 31 at 10:57

# Pepe, 13 bytes

REEeREEEeReEe


Try it online! Disable "Separated by" check box below the input text box.

Explanation:

REEe  # Input as string (stack R)
REEEe # Goto last char (stack R)
ReEe  # Output char (stack R)