57 votes

I'm a palindrome. Are you?

Pyth, 3 bytes _I_ Returns True or False. Try it online! How it works ...
Dennis's user avatar
  • 210k
50 votes

I'm a palindrome. Are you?

Python, 39 bytes lambda s:s[::-1]==s#s==]1-::[s:s adbmal Try it online! Boring, but if there is shorter in Python it will be impressive.
Jonathan Allan's user avatar
35 votes

I'm a palindrome. Are you?

Jelly, 5 bytes ḂŒ ŒḂ Returns 1 or 0. The first line is an unexecuted helper link, the second line calls the palindrome test. Try it online!
Dennis's user avatar
  • 210k
34 votes

Palindrome Hello, World

///, 37 bytes Greetings, Planet!/!tenalP ,sgniteerG
Dennis's user avatar
  • 210k
32 votes
Accepted

Watson-Crick palindromes

05AB1E, 10 7 bytes Code: Â'š×‡Q Explanation: To check if a string is a palindrome, we just need to check the input with the input, with ...
Adnan's user avatar
  • 44.3k
30 votes

Goodness Giza Golf!

Python 2, 48 47 46 bytes lambda s:s[~len(s)/2:]in'987654321'>s==s[::-1] Test it on Ideone. How it works In Python, a chained comparison returns True if and ...
Dennis's user avatar
  • 210k
25 votes

I'm a palindrome. Are you?

Jelly, 5 bytes ⁼ṚaṚ⁼ Try it online! Equals reverse and reverse equals. Or the more efficient yet less aesthetically pleasing: ...
Jonathan Allan's user avatar
24 votes

I'm a palindrome. Are you?

Haskell, 87 85 44 34 bytes p=(==)<*>reverse--esrever>*<)==(=p Explanation: ((->) a) is an instance of ...
Program man's user avatar
23 votes

I'm a palindrome. Are you?

05AB1E, 3 bytes Code: ÂQÂ Explanation: ...
Adnan's user avatar
  • 44.3k
23 votes

I'm a palindrome. Are you?

Mathematica, 23 bytes QemordnilaP;PalindromeQ Not very interesting, but for the sake of completeness... The above is a ...
Martin Ender's user avatar
22 votes

Goodness Giza Golf!

Perl, 39 37 42 39 + 1 = 40 bytes Using a new method, I managed to cut down a huge number of bytes. Run with the -n flag. Accepts input repeatedly at runtime, ...
Gabriel Benamy's user avatar
20 votes

User Appreciation Challenge #1: Dennis ♦

Jelly, 11 bytes ŒufØAe€ØCŒḂ Try it online! Alternate versions: ŒlfØae€ØCŒḂ ...
Erik the Outgolfer's user avatar
19 votes

Watson-Crick palindromes

Jelly, 9 bytes O%8µ+U5ḍP Try it online! or verify all test cases. How it works ...
Dennis's user avatar
  • 210k
19 votes

I'm a palindrome. Are you?

PHP, 55 bytes <?=strrev($s=$argv[1])==$s;#;s$==)]s[TEG_$=s$(verrts=?< Try it online!
Cave Johnson's user avatar
19 votes
Accepted

Yo boy, must it sum

Brachylog, 7 bytes ~+ℕᵐ.↔ᵐ Try it online! Surprisingly not that slow. Explanation ...
Fatalize's user avatar
  • 38.4k
18 votes

Heterograms, Palindromes, oh my!

Pyth, 17 bytes Z.{rzZ.q.Zzr}.Z Try it online here. The leading space is necessary. I have counted it and the trailing space in the byte count. Here's the ...
Mike Bufardeci's user avatar
18 votes

User Appreciation Challenge #1: Dennis ♦

05AB1E, 9 bytes žM¹álSåÂQ Try it online! -2 thanks to Adnan. This attacks Jelly's pain point exactly. It uses l and ...
Erik the Outgolfer's user avatar
18 votes

User Appreciation Challenge #1: Dennis ♦

x86 32-bit machine-code function, 42 41 bytes Currently the shortest non-golfing-language answer, 1B shorter than @streetster's q/kdb+. With 0 for truthy and non-zero for falsy: 41 40 bytes. (in ...
Peter Cordes's user avatar
  • 4,757
17 votes

Heterograms, Palindromes, oh my!

Python 3, 125 The main problem is to make the reverse of the code parsable. Then we can let it error out from undefined identifiers. ...
feersum's user avatar
  • 31.3k
17 votes

Palindromize this string!

Python 3, 41 bytes lambda t:t+t[-2::-1]#]1-::2-[t+t:t adbmal Try it here.
Luis Mendo's user avatar
  • 104k
17 votes

I'm a palindrome. Are you?

MATL, 7 bytes tPX=XPt Try it online! Returns [1; 1] for palindromic input and [0; 0] otherwise. ...
B. Mehta's user avatar
  • 753
17 votes

Palindromic Primes without 11

Python 2, 76 73 72 70 69 68 bytes n=input();c=k=m=11 while n:m*=k/c;k+=c;n-=`k`==`k`[::~m%k-c] print k Thanks to @WheatWizard for golfing off 3 bytes! Thanks to ...
Dennis's user avatar
  • 210k
17 votes

Palindromic numbers with a binary twist

05AB1E, 7 bytes b0Ü‚DíQ Try it online! or as a Test Suite Explanation ...
Emigna's user avatar
  • 52.9k
16 votes

Palindrome Hello, World

TI-BASIC, 67 bytes "!tenalP ,sgniteerG" "Greetings, Planet!" This works because the last line of a program is displayed on the screen, while the first string is ...
NinjaBearMonkey's user avatar
16 votes

Palindromize this string!

05AB1E, 1 byte û Try it online!
Luis Mendo's user avatar
  • 104k
16 votes

I'm a palindrome. Are you?

Pip, 12 11 bytes Now comment-free! x:RVaQaVR:x Takes input as a command-line argument; outputs 1 for palindrome, ...
DLosc's user avatar
  • 38k
16 votes

Have you heard of tralindromes?

Regex (Perl / PCRE2 / Boost / Pythonregex), 59 47 46 38 37 33 32 bytes ^((.+)((.)(?3)\4|(?=\2$).?))?.?$ Try it online! - Perl ...
Deadcode's user avatar
  • 11.5k
15 votes

Palindromizing the strings

Pyth (commit b93a874), 11 bytes .VkI_IJ+zbB Test suite This code exploits a bug in the current version of Pyth, commit b93a874. The bug is that ...
isaacg's user avatar
  • 42k
15 votes
Accepted

Write a Palindrome-Polyglot-Quine

CJam/GolfScript, 2 languages, 50 bytes {`"0$~e#"+0$-1%"":n}0$~e##e~$0}n:""%1-$0+"#e~$0"`{ Try it CJam! Try it in GolfScript! Huh, this went unanswered ...
Martin Ender's user avatar

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