'abc' and 'cba'

Question

Your task is simple, write a single code snippet that when executed in one language outputs only the string 'abc' and when executed in another language outputs only the string 'cba'. The program should take no input.

This is a code-golf challenge.

Answer 1

05AB1E / Pyth, 5 bytes

_"abc

Try 05AB1E online!

Try Pyth online!

This also works in Pyke, outputting cba.

This also works in Recursiva, outputting cba.

Answer 2

MATLAB / Octave, 41 bytes

disp(flip('abc',size(randsample(2,2),2)))

In MATLAB randsample(2,2) gives a 2×1 vector, so size(...,2) is 1. Thus flip is applied along the first dimension, which is a singleton, so the original string 'abc' is displayed:

In Octave randsample(2,2) gives a 1×2 vector, so size(...,2) is 2. Thus flip is applied along the second dimension, that is, the string is flipped from left to right:

Answer 3

25 bytes

print(1/2and'cba'or'abc')

Try it online! (Python 2)

Try it online! (Python 3)

Answer 4

Whitespace and Bash, 57 bytes

   		    	
 
 	
     	
	    
 	
     	
	   	
echo  cba

Try it online!

Answer 5

-1 byte if I make ==0 into >0 but that's already another answer

Python 2, 26 bytes

print('acbbca'[1/2==0::2])

Try it online!

---

Python 3, 26 bytes

print('acbbca'[1/2==0::2])

Try it online!

1/2 gives 0 (floordiv) in Python 2 and 0.5 (truediv) in Python 3. Thus, 1/2==0 gives 1 in Python 3 and 0 in Python 2 (actually, booleans, but those are just integers), so 'acbbca'[1::2] => 'cba' is given for Python 3 and 'acbbca'[0::2] => 'abc' is given for Python 2.

Answer 6

Excel / Google Sheets, _{41 28 27} 24 Bytes

Anonymous worksheet formula that takes no input and outputs "ABC" to the calling cell in Excel and "CBA" to the calling cell in Google Sheets

=IfError(M("CBA"),"ABC")

In Google Sheets, M(...) is an alias for and autoformatted to T(...) (short for Text()). This call returns the text value of the passed variable, "CBA". "CBA" is not caught as an error, so "CBA" is returned by IfError(...,"ABC")

In Excel, there is no M(...) function, and M(...) is not an alias and therefore M("CBA") returns the formula not found error, #NAME?. This is caught by IfError(...,"ABC"), which in turn returns "ABC".

---

Previous Versions, 27, 28, 41 Bytes

See edits for explanations

=If(IsErr(A()),"ABC","CBA")

=If(IsErr(GT()),"ABC","CBA")

=IfError(If(Info("NUMFILE"),"ABC"),"CBA")

Answer 7

With apologies to @HyperNeutrino for stealing most of his answer (I don't have the reputation to comment yet)

Python 2, 25 bytes

print('acbbca'[1/2>0::2])

Try it online!

Python 3, 25 bytes

print('acbbca'[1/2>0::2])

Try it online!

Answer 8

CJam / 05AB1E, 6 bytes

"abc"R

Try it online:

• CJam;
• 05AB1E.

How it works in CJam

"abc"    Push this string
R        Push variable R, predefined to the empty string
         Implicitly display stack

How it works in 05AB1E

"abc"    Push this string
R        Reverse
         Implicitly display top of the stack

Answer 9

Vim / Notepad.exe, 10 bytes

cbaabc<esc><backspace><backspace><backspace>

Answer 10

JavaScript (NodeJS) and PHP, 46 bytes

<!--
strrev=console.log//--><?=
strrev("abc");

Prints abc in JS and cba in PHP.

Try the JS online!

Try the PHP online! (note that TIO doesn't hide the HTML comments (<!--...-->)

Answer 11

Python / Befunge, 20 18 bytes

2 bytes saved thanks to @karhell

print("abc")# ,,,@

Try it online! for Python

Python sees print("abc") then a comment.

Try it online! for Befunge

Befunge, removing all nops and useless commands sees "abc",,,@ which puts a, b and c on the stack and then prints them (last in - first out).

Answer 12

Python 2 and Python 3, 42 bytes

try:exec("print'abc'")
except:print('cba')

Try it online! (Python 2)

Try it online! (Python 3)

Thought I'd try something different...

Answer 13

Excel/Google Sheets, 28 bytes

Inspired by @TaylorScott, who used a function that only exists in Excel, I found an even shorter function that only exists in Google Sheets. Conveniently, it is designed to return strings:

=iferror(join(,"cba"),"abc")

How it works

In Google Sheets, join([arg1], arg2, arg3,...argk) will concatenate arg2 -> argk, optionally using the separator specified in arg1. In this case, it successfully returns "cba."

Excel has no join function, so iferror sees a problem and returns "abc"

Answer 14

C and C++, 115, 78, 58, 56 bytes

#include<stdio.h>
main(){puts(sizeof('x')>1?"abc":"cba");}

78 bytes, thanks to challenger5.

58 bytes, thanks to aschepler.

56 bytes, thanks to hvd

Try it - C++!

Try it - C!

Answer 15

CJam and Gaia, 8 bytes

'c'b'a]$

Try it in CJam!

Try it in Gaia!

Explanation

In both languages this defines a list of characters.

In CJam, $ is sort, so it becomes abc.

In Gaia, $ joins the list into one string, giving cba.

Answer 16

Java 8 & C, 95 bytes

//\
interface a{static void main(String[]s){System.out.print("abc"/*
main(){{puts("cba"/**/);}}

Try it in Java 8 - resulting in "abc".
Try it in C - resulting in "cba".

Explanation:

//\
interface a{static void main(String[]s){System.out.print("abc"/*
main(){{puts("cba"/**/);}}

As you can see in the Java-highlighted code above, the first line is a comment due to //, and the C-code is a comment due to /* ... */, resulting in:

interface a{static void main(String[]s){System.out.print("abc");}}

---

//\
interface a{static void main(String[]s){System.out.print("abc"/*
main(){{puts("cba"/**/);}}

Not sure how to correctly enable C-highlighting, because lang-c results in the same highlighting as Java.. But //\ will comment out the next line, which is the Java-code, resulting in:

main(){{puts("cba");}}

Answer 17

Python 2 / Python 3, 28 bytes

print('abc'[::int(1/2*4)-1])

In Python 2 int(1/2*4)-1 evaluates to -1 and so prints cba. - TiO

In Python 3 it evaluates 1 so prints abc. - TiO

Answer 18

R/Cubix, 20 bytes

cat("abc")#u@o;o;o(;

R - Try it online!

Cubix - Try it online!

For R, cat("abc") then shameless abuse of comments. For Cubix

    c a
    t (
" a b c " ) # u
@ o ; o ; o ( ;
    . .
    . .

• "abc" Pushs a, b ad c onto the stack
• )# Increment the c, pushs number of element in stack
• u U-turn to the right
• ;( Remove the count, Decrement the c
• o;o;o@ Output cba and exit

Pushs the number on in stack

Answer 19

Python 3, 26 bytes

print('abc'[::-(1/2>0)|1])

Try it online!

Python 2, 26 bytes

print('abc'[::-(1/2>0)|1])

Try it online!

25-byte version with exit instead, which outputs to STDERR instead.

This is basically the same as print('abc'[::[1,-1][1/2>0]]), just that it's golfed.

Answer 20

Ly / ><>, 20 19 bytes

"abc"&&ov
;     oo<

Try it with ><>!

Try it with Ly!

These languages are very similar, as Ly is based off ><>. However, Ly does not have 2D execution and interprets & differently, which I took advantage of here.

Both languages will start by pushing abc to the stack.

For ><>, the & instruction moves values to and fro the register. Two in a row will push a value to the register and then take it straight back, essentially a NOP.

For Ly, & is a modifier that makes an instruction perform its function on the entire stack.

o means the same thing for both languages, but since it is modified by & in Ly, it will print the whole stack, outputting abc. In ><>, it will only output c (as it is printed from the top down)

v is a NOP in Ly, which skips it and goes straight to ;, ending execution. ><> will instead treat it as a pointer, sending the IP downwards.

It then hits another arrow, sending the IP left. Here, it meets two o signs, outputting b and a.

EDIT: Saved a byte (and fixed ><> crashing)

Answer 21

Python 2 and Foo, 16 bytes

print"abc"[::-1]

Python 2

print"abc"[::-1]

Try Python 2 online!

Explanation

print"abc"[::-1]

print             # print... (duh)
     "abc"        # the string "abc"...
          [::-1]  # backwards

Foo

"abc"

Try Foo online!

Explanation

"abc"

"abc"               print the string "abc"

Answer 22

C (gcc) C++ (g++), 59 bytes

#include<stdio.h>
main(){puts("abc\0cba"+(sizeof(' ')&4));}

Answer 23

Fission / ><> , 11 bytes

!R"abc"ooo;

Try Fission Online

In Fission, a particle starts at R and prints abc.

Try ><> Online

In ><>, the IP starts at the top-left. ! skips the next instruction, and "abc" pushes [a,b,c] on the stack. ooo then pops and prints three times, giving cba.

Both programs end at ;

Answer 24

Japt 2.0/JavaScript, 11 10 bytes

"abc"
//Uw

Japt 2.0 outputs cba

JavaScript outputs abc

Answer 25

J/K (Kona), 30 bytes

NB. :`0:"ABC"
{}[] /.echo'CBA'

TIO - J & TIO - K kona

Answer 26

CJam and ><>, 12 bytes

"ooo;abc
"4>

What CJam sees:

"ooo;abc
"

String literal, which pushes the string ooo;abc (with a trailing newline) to the stack.

 4>

Slice off the first four characters of the string, leaving abc, which is output.

What ><> sees:

"

Begins a string literal.

 ooo;abc

Forms the contents of the string literal. The character codes of the characters in the string are pushed to the stack in reverse order (so c is on the top).

"

The IP wraps around, hitting the " a second time, which ends the string literal.

 ooo

Outputs the top three characters on the stack: cba

    ;

Terminates the program. Neither the abc nor any part of the second line is executed.

Solution with Error: 8 bytes

"abc"oo<

What CJam sees (Try it online!):

"abc"

Push a string literal to the stack.

    o

Output that string literal.

     o

Try to output again. The stack is empty, so the program crashes.

What ><> sees:

"abc"

Push three characters onto the stack in reverse order.

    o

Print one character: c

     o

Print another character: b

      <

Start moving backwards.

     o

Print the last character: a

    o

Try to print another character. Since the stack is empty, the program errors.

Answer 27

05AB1E and 2sable, 6 bytes

…CBAžR

Prints ABC (OP said it was allowed) in 05AB1E and CBA in 2sable, using the fact that 2sable was similar to 05AB1E but the žR was added to 05AB1E after 2sable was abandoned.

Try it online! (05AB1E)

Try it online! (2sable)

Answer 28

PHP + JavaScript, 29 28 bytes

This works because PHP interprets '0' (same as the integer number 0) as being falsy, while JavaScript assumes it is simply a non-empty string which is truthy.

'0'?alert('cba'):print(abc);

This is meant to run with -r on PHP. In Javascript, just paste it in the console.

---

Thanks to @Justin Mariner for saving me 1 byte!

Answer 29

PHP / Brainf*ck, 31 bytes

using the -r flag,

PHP sees die(abc) and a comment, and since the compiler is forgiving, it outputs abc as a string instead of an empty variable.

Brainf*ck only sees the instruction characters, and the rest is seen as comments.

die(abc);#--[----->+<]>---.-.-.

Try it online! (PHP)

Try it online! (Brainf*ck)

Answer 30

Julia and Octave/Matlab, 27 bytes

if'a'=="a""abc"else"cba"end

In Octave, both 'a' and "a" represent the same string, therefore 'a'=="a" is true. However, in Julia, 'a' is a single character while "a" is a one-character string. In Julia, "cba" is the output.

Ungolfed version:

if 'a'=="a"
  "abc"
else
  "cba"
end

Answer 31

Perl / Ruby, 18 bytes

Ruby

print'abc'.reverse

prints cba as we're calling .reverse on the string.

Try it online!

Perl

print'abc'.reverse

prints abc concatenated with the result of reverse which by default works on $_ which is empty and so makes no difference.

Try it online!

Answer 32

Python and Ruby, 30 bytes

print(['abc','cba'][(0 or 1)])

Ruby: the logical or short-circuits on 0, which is a truthy value.

Python: 0 is false, and the logical or yields 1.

Answer 33

Python 2, 27 bytes

print(['abc','cba'][1/2>0])

Try it online!

Python 3, 27 bytes

print(['abc','cba'][1/2>0])

Try it online!

Answer 34

Python 2 and Python 3, 31 bytes

print(round(.5)and"abc"or"cba")

Uses the and/or trick from Erik the Outgolfer's answer, as well as the fact that Python 3 uses banker's rounding, while Python 2 does not.

Try it - Python 2!

Try it - Python 3!

Answer 35

Python 2, 28 bytes

print("abc"[::1/2and-1or 1])

Try it online!

Python 3, 28 bytes

print("abc"[::1/2and-1or 1])

Try it online!

Answer 36

JavaScript (ES8 & ES6), 24 bytes

_=>"".padEnd?"abc":"cba"

Answer 37

05AB1E and MY, 22 bytes

Try it online! (05AB1E)

Hex String in Python:

'"abc"?\x8e\x01\x06\x89(\x02\x06\x89(\x80\x03\x06\x89(\x80&'

Rendered in 05AB1E's codepage:

"abc"?Žʒε‰(αε‰(€βε‰(€&

Rendered in MY's unimplemented codepage:

_RrH_⌈≡16ǵ'26ǵ'+36ǵ'+←

How?

Here is what 05AB1E sees:

"abc"?Žʒε‰(αε‰(€βε‰(€&
"abc"                   -  The string "abc"
     ?                  -  Print (no newline)
      Ž                 -  Break on empty stack
       ʒε‰(αε‰(€βε‰(€&  - Unread junk

What MY sees (I added a feature which causes errors to produce 0, in addition to fixing the r command.):

_RrH_⌈≡16ǵ'26ǵ'+36ǵ'+←
_                       Negate (0)
 R                      Convert to binary ([0])
  r                     Convert from binary (0)
   H                    Convert to hex ("0")
    _                   Negate (errors, so 0)
     ⌈                  Ceiling (0)
      ≡                 Match (0 0=>1)
       16ǵ'             'a'
           26ǵ'+        Prepend 'b'
                36ǵ'+   Prepend 'c'
                     ←  Output without a newline

I could have used …, but I don't want to divide by 0 to result in 0.

(Use the file polyglot.py)

Answer 38

Braingolf and Lean Mean Bean Machine, 35 bytes

 O
""
#a
!$
""
#b
!$_
""
#c
& ,&
@U

Braingolf: Try it online!
No LMBM online interpreter available

Outputs abc in LMBM, and cba in Braingolf.

Explanation

LMBM is a 2d language, which allows us to selectively execute the code we want.
Meanwhile Braingolf is a 1d language, meaning it starts at the top left, and goes across each line, executing code. It terminates upon reaching the end of the code.

In LMBM, a marble is spawned at every uppercase O when the program starts. Each tick it drops 1 character and executes the character. LMBM terminates once all marbles are destroyed.

A double quote " in LMBM sets the marble to char mode, meaning the next character to execute is interpreted as a 1 char string literal, and the marble's value is set to the codepoint of the character.

However " begins and terminates a string in Braingolf, automatically pushing the contents to the stack. Thankfully an empty string does nothing.

$ in LMBM prints the marble's value as a char, however this is the silent modifier in Braingolf, so we have to make sure to consume that modifier before we try to print the stack, that's what the ! and _ are for (_ pops and prints the top of the stack, with the $ modifier it doesn't print, and with the ! modifier it doesn't pop, so !$_ consumes both modifiers without actually doing anything)

In Braingolf # is the char literal identifier, causing the codepoint of the next char to be pushed to the stack.

After passing through all of the characters (and in LMBM's case printing the first 2) we hit the last 2 lines.
The 2nd to last line does nothing in LMBM, as it simply drops through the space, a no-op.

In Braingolf however, the ampersand & is the greedy modifier. Modifiers in Braingolf are held until an operator consumes them, so the first ampersand is held through the space until it hits the comma , Braingolf's flip operator. The greedy modifier is consumed here to cause Braingolf to flip the entire stack, rather than the top 2 items. Then another greedy modifier is hit.
This one is held through the newline to the at @ sign, this prints the entire stack as ASCII.

Meanwhile LMBM simply drops through the space into the U, which prints the marble's value as ASCII and destroys the marble.
The U also has a function in Braingolf, it pops the top of the stack and pushes range(0...n), but the stack is empty because we just popped and printed everything, so this does nothing.

Answer 39

C / Common Lisp, 91 88 40 36 bytes

//(princ"abc")
;main(){puts("cba");}

Try it online – C

Try it online – Common Lisp

Both “normal” languages with very different syntax and semantics!

Explanation

For Common Lisp:

// is a special variable used in the Common Lisp REPL to give the result of the value preceding the previous one, initially equal to NIL. Then we prints abc. The following line starts with a semicolon, which is used to start one-line comments.

For C:

the first line is a comment, and the other is the program. Note that the semicolon before the definition of the main function is syntactically correct.

-1 byte thanks to @Zacharý

Answer 40

Javascript / Ruby, 28 bytes

''?print('abc'):alert('cba')

A shorter version without prints for interpreters (14 bytes) :

''?'abc':'cba'

Explanation

NEW VERSION: '' is falsy for Javascript, but truthy for Ruby.

OLD VERSION: For Javascript, []+[] = "" as a string concatenation, since the + operand is only defined for numbers and strings, and the empty string is evaluated as false

Meanwhile, in Ruby, you can concatenate array using the + operand, and it is evaluated as true

_{(first participation in PCG ! :))}

Answer 41

C/><>, 58 bytes

#include <stdio.h>//^
int main(){puts(/*/*/"abc"//ooo;
);}

Answer 42

V/Vim, 6 bytes

iabcæ

Try it online!

V: cba

Vim: abc

V and Vim are backwards compatible, but V has many more commands mapped. In V, æ means <M-f>lip where it's meaningless in Vim.

Answer 43

JavaScript / Pascal, 40 bytes

JavaScript

Outputs "abc".

{alert`abc`/*}begin write('cba')end.{*/}

---

Pascal

Outputs "cba".

{alert`abc`/*}begin write('cba')end.{*/}

Try it online!

---

Pascal conveniently uses { } for block comments and, in JavaScript, { } are just scopes, which affect nothing in this context.

Answer 44

C and x86 DOS binary, 58 bytes

/* VX4!PZSXNN4s(D (D"5s@SCYAAA@!6cba*/main(){puts("abc");}

Answer 45

Pyth / Canvas, 14... bytes?

<4"abcｊｊｊ±" \┐

Try it in Pyth!
Try it in Canvas!

---

Pyth explanation:

<4                # All but the last 4 characters of:
  "abcｊｊｊ±"   　# String literal
               \┐ # Char literal, printing suppressed

Python 3 translation:

print("abcｊｊｊ±"[:-4])
"┐"

---

Canvas explanation:

Code               | Explanation                         | Stack
-------------------+-------------------------------------+----------------
<4"abc             | Push "<4\"abc" to the stack         | "<4\"abc"
      ｊｊｊ        |Remove first three characters of ToS | "abc"
           ±       | Reverse ToS                         | "cba"
             " \   | Push "\" \\" to stack               | "cba", "\" \\"
                 ┐ | Remove ToS                          | "cba"
                   | Print ToS (implicit)                |

Answer 46

brainfuck / Jelly, 24 bytes

-[+[>+<<]>+]>+.+.+.
“CBA

“ is encoded as 0xFE in Jelly's codepage. Jelly's codepage is backwards compatible with printable ASCII, so all other characters are encoded the same.

To brainfuck

Try it online!

-[+[>+<<]>+]> sets a cell to 64. +.+.+. increments and outputs three times, printing ABC.

To Jelly

Try it online!

The first line is parsed as valid Jelly, but is ignored.

The second line is a string literal with content CBA. The last line of the file is the main link, so this is printed.

Answer 47

Swift / JavaScript, 34 bytes

/*/*/alert`cba`// */*/print("abc")

Try it Online! (Swift)

Testing snippet (JavaScript):

/*/*/alert`cba`// */*/print("abc")

This works by abusing nested block comments in Swift. Swift interprets the code as /*/* Comment */*/print("abc") while JavaScript interprets the code as /*Comment*/alert`cba`//Comment

Answer 48

Japt/Japt 2.0, 14 bytes

;AÊ?"abc":"cba

Japt outputs cba

Japt 2.0 outputs abc

Answer 49

JScript, VBScript, 42 bytes

rem=1;a="abc"/*
a="cba"'*/
WScript.echo(a)

Answer 50

C / ><>, 33 bytes

#//;ooo"cba"
main(){puts("abc");}

What C sees

Try it online!

#
​

Begin empty preprocessor directive.

//;ooo"cba"
​

Single-line comment.

main(){puts("abc");}

Print abc.

What ><> sees

Try it online!

#
​

Reflect the code in the other direction.

       "cba"
​

String literal. Push the character codes of abc to the stack in order.

    ooo
​

Output each of those characters. Since c is at the top of the stack, it is output first.

   ;
​

End the program.

 //
main(){puts("abc");}

Never executed.

Answer 51

><> and Underload, 14 bytes

"(abc)S"}}ooo;

To ><>:

Try it online!

"(abc)S"

String literal. Push the character codes of (abc)S to the stack.

        }}

Move the TOS to the bottom twice.

          ooo

Output three characters (cba).

             ;

Halt.

To Underload:

https://tio.run/##K81LSS3KyU9M@f9fSSMxKVkzWKm2Nj8/3/r/fwA

"

Unrecognized

 (abc)

Push the string abc.

      S

Output it.

       "}}ooo;

More unrecognized characters.

Answer 52

Javascript and Japt, 18 15 bytes

$Pw=P="cba";$Pw

Outputs "abc" in Japt and "cba" Javascript.

Try it online!

Answer 53

Add++/Whispers v2, 29 bytes

x:"abc"
O
> "cba"
>> Output 1

Try Add++ online!

Try Whispers online!

This exits with an exit code of 1 when run in Add++.

How it works

Add++

Add++ goes through each line in a linear fashion, executing as it does so. The first line

x:"abc"

sets the x variable to the string abc. Then

O

outputs that string. Next

> "cba"
>> Output 1

(the Whispers code), compares the strings abc and cba lexicographically before throwing an error at the double >> on the fourth line.

Whispers

Whispers removes any lines which don't match one of it's five regexes, all of which only match lines beginning with >, making the code processed by Whispers

> "cba"
>> Output 1

Whispers' execution model is almost the exact opposite of Add++; it begins at the bottom line, and calls the lines indicated by the numbers as arguments.

>> Output 1

calls the function stored on line 1, then outputs the result. Line 1 is

> "cba"

, a nilad line which returns a single value and takes no arguments. Here, it returns the string cba, which is then outputted by the last line.

Answer 54

PHP & HTML, 15 bytes

<?die(abc)?>cba

PHP exits with printing abc; cba is ignored.
HTML sees the PHP code as unrecognized tag (and ignores it), then prints cba.

Answer 55

Python 3 and Batch, 24 bytes

print('abc')#|echo cba

This program just takes advantage of operators in both languages.

What Python Sees

print('abc') # This is a comment, do not run

What Batch Sees

oh noes! errors! run this -> echo cba

Answer 56

Tcl, 79 bytes

#include<stdio.h>/*
proc M {} {puts cba}
#*/
#define M main(){printf("abc");}
M

Try it online!

---

C (gcc), 79 bytes

#include<stdio.h>/*
proc M {} {puts cba}
#*/
#define M main(){printf("abc");}
M

Try it online!