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Questions tagged [string]

A competition to solve a particular problem through the usage and manipulation of strings.

387
votes
729answers
112k views

“Hello, World!”

So... uh... this is a bit embarrassing. But we don't have a plain "Hello, World!" challenge yet (despite having 35 variants tagged with hello-world, and counting). While this is not the most ...
358
votes
36answers
50k views

Covfefify a string

In this challenge, you must take a string matching the regex ^[a-zA-Z]+$ or whatever is reasonable (you don't have to consider uppercase or lowercase letters if you ...
321
votes
1answer
104k views

Regex that only matches itself

There are some pretty cool challenges out there involving regex (Self-matching regex, Regex validating regex) This may well be impossible, but is there a regex that will ONLY match itself? NOTE, ...
188
votes
56answers
15k views

No A, just CAPS LOCK

What happens when the CapsLock key on your keyboard doesn't have a notch in it? "This hPPENS." The goal of this program is to consistently emulate keyboard misses where each A press is replaced with ...
171
votes
47answers
27k views

Mathematics is fact. Programming is not

In mathematics an exclamation mark ! often means factorial and it comes after the argument. In programming an exclamation mark !...
165
votes
25answers
19k views

Do you want to code a snowman?

Here is a simple ASCII art snowman: _===_ (.,.) ( : ) ( : ) Let's make him some friends. This will be the general pattern for our ASCII art snowpeople: ...
157
votes
122answers
30k views

Trick or Treat polyglot

Since Halloween is coming up I thought I might start a fun little code golf challenge! The challenge is quite simple. You have to write a program that outputs either ...
153
votes
145answers
51k views

Don't google “google”

We all know that if you google the word "google" it will break the internet. Your task is to create a function that accepts one string and returns its length, in the fewest possible Unicode ...
132
votes
239answers
34k views

1, 2, Fizz, 4, Buzz

Introduction In our recent effort to collect catalogues of shortest solutions for standard programming exercises, here is PPCG's first ever vanilla FizzBuzz challenge. If you wish to see other ...
126
votes
71answers
15k views

Hello, World! (Every other character)

Write a program that prints "Hello, World!". But also, if you take only the first, third, fifth, etc. characters of your program, the resulting program should still print "Hello, World!". If your ...
115
votes
176answers
28k views

Sing Happy Birthday to your favourite programming language

Your favourite programming language has just had a birthday. Be nice and sing it the Happy Birthday song. Of course you should accomplish this by writing a program in that language. The program takes ...
115
votes
36answers
22k views

La La Land… no wait, Moo Moo Moonlight

This challenge is a tribute to the winner of Best Picture at the Oscars 2017, La La Land Moonlight! Write a function/program that takes a string containing only letters ...
113
votes
52answers
25k views

GO OUT AND VOTE

Today is November 8th, 2016, Election Day in the United States of America. If you are a U.S. citizen eligible to vote, then go out and vote if you haven't already before answering this challenge. Do ...
102
votes
66answers
25k views

I'm a palindrome. Are you?

There have been a couple of previous attempts to ask this question, but neither conforms to modern standards on this site. Per discussion on Meta, I'm reposting it in a way that allows for fair ...
93
votes
14answers
19k views

I am passive aggressive and want to insult my boss without him finding out

It's been a rough few months at work and I feel like I just want to scream right to my boss' face. I am, however, not one to directly confront people I have a problem with. I also don't want to lose ...
92
votes
52answers
13k views

Make a “Ceeeeeeee” program

Once I wrote a JavaScript program that would take as input a string and a character and would remove all characters except for the first one and the character given as input, one by one. For example, ...
85
votes
9answers
5k views

Golf an Advent Calendar

It's that time of year when many of us get our advent calendars! If you are unfamiliar with an advent calendar, these are special calendars used to count down advent in anticipation of Christmas. In ...
84
votes
28answers
4k views

Vertically collapse text

Say I have text like this (each word on one line, with no spaces) Programming Puzzles & Code Golf That makes no sense! It totally defies the laws of physics. ...
83
votes
128answers
10k views

Determine whether strings are anagrams

Challenge Given two strings, work out if they both have exactly the same characters in them. Example Input word, wrdo This returns true because they are the ...
83
votes
13answers
7k views

Z̡̬a̧̯̔l̆̓g̛̘̟o̡ generator

Write a program or function that transforms an input string into Zalgo text. For example, for an input string Zalgo, a possible output might look like: ...
82
votes
76answers
9k views

Unique is Cheap

Write a function or program that determines the cost of a given string, where the cost of each character equals the number of how many times the character has occurred up to this point in the string,...
80
votes
254answers
15k views

Simple cat program

One of the most common standard tasks (especially when showcasing esoteric programming languages) is to implement a "cat program": read all of STDIN and print it to STDOUT. While this is named after ...
78
votes
39answers
13k views

What my dog really hears

My dog is called Rex. Every time I scold him, he seems not very impressed and the only times I see him react is when I pronounce his name. If I say ...
77
votes
126answers
11k views

Print a Tabula Recta!

Print a Tabula Recta! The Tabula Recta (sometimes called a 'Vigenere Table'), was created by Johannes Trithemius, and has been used in several ciphers, including all variants of Bellaso's Vigenere ...
76
votes
91answers
10k views

N(e(s(t))) a string

To "function nest" a string, you must: Treat the first character as a function, and the following characters as the arguments to that function. For example, if the input string was ...
75
votes
127answers
21k views

The shortest code to invert bit-wise a binary string

Me thinks there aren't enough easy questions on here that beginners can attempt! The challenge: Given a random input string of 1's and 0's such as: ...
75
votes
54answers
6k views

From Programming Puzzles to Code Golf

Your task is to write a program that outputs the exact string Programming Puzzles (trailing newline optional), but when all spaces, tabs, and newlines are removed ...
74
votes
45answers
13k views

Code Johnny Code, Code!

Rock-and-roll founding father Chuck Berry sadly passed away today. Consider the chorus of his famous song "Johnny B. Goode": ...
73
votes
86answers
16k views

Build me a brick wall!

Challenge I need help building a brick wall! Throw together some code for me using no input and produce the following output wall shown below: ...
72
votes
35answers
11k views

Non-discriminating Programming

We say a string is non-discriminating if each of the string's characters appears the same number of times and at least twice. Examples "aa!1 1 !a !1" is non-...
71
votes
39answers
7k views

Happy Birthday V!

Thanks to @KritixiLithos for helping me out with this challenge! V is a programming language that I wrote so that I could use and extend vim for code-golf challenges. The very first commit was on ...
71
votes
21answers
8k views

Turtles All the Way Down

Write a program or function that takes in a positive integer and prints or returns a stack of that many ASCII-art turtles, where each turtle is larger than the one above it. Specifically, if the ...
71
votes
27answers
6k views

2016 Time Capsule String: How Versatile Is Your Language?

About a year ago on Dec 31, 2015, I had the idea that: We should make a time capsule string. Everybody gets to add one character and next new years we'll see who can make the best program out of ...
71
votes
36answers
4k views

Uncollapse digits

Task Given a string of English names of digits “collapsed” together, like this: zeronineoneoneeighttwoseventhreesixfourtwofive Split the string back into digits:...
69
votes
111answers
14k views

Print the alphabet without using each vowel

Inspiration: in 1939, a man named Ernest Vincent Wright wrote a novel called Gadsby without using the letter 'e'. Your task is to write a set of (up to 5) programs in any language (which has a text-...
69
votes
133answers
14k views

“99 Bottles of Beer”

Write a program that outputs the lyrics to 99 Bottles of Beer, in as few bytes as possible. Lyrics: ...
69
votes
10answers
6k views

Rock, Polyglot, Scissors

Write a program that is a polyglot in three languages that plays rock–paper–scissors. The input for any version of the program is always one of the strings rock or ...
67
votes
51answers
13k views

War is peace. Freedom is slavery. Ignorance is strength

As George Orwell wrote in 1984: War is peaceFreedom is slaveryIgnorance is strength Write a program or function that takes in one of the six main words from the Orwell quote and outputs its ...
66
votes
69answers
9k views

Count of “a”s and “b”s must be equal. Did you get it computer?

In the popular (and essential) computer science book, An Introduction to Formal Languages and Automata by Peter Linz, the following formal language is frequently stated: mainly because this language ...
65
votes
55answers
12k views

Hare Krishna Hare Krishna Krishna Krishna Hare Hare

Recently, I've seen Hare Krishna people with their mantra on the emblem and I've found it may be quite interesting to code golf. The challenge Write the Hare Krishna mantra, i.e.: ...
65
votes
41answers
4k views

Golfing A Weasel Program

Richard Dawkins in his book The Blind Watchmaker, describes a Weasel program. The algorithm can be described as follows: Start with a random string of 28 characters. Valid characters are all ...
64
votes
22answers
11k views

The kitten command

A kitten is much like a cat. Some of the main differences are cuteness, lack of intelligence, and size. Similarly, the cat command is different from the ...
61
votes
38answers
9k views

Uncomment a COBOL program!

COBOL is a very old language, at the time of writing it is 58 years old. It is so old, in fact, that it has a very interesting quirk: the first six characters of each line are comments. Why is this, ...
59
votes
18answers
8k views

All in all it's just, uh, another trick in code golf

The purpose of this challenge is to produce an ASCII version of the cover of this great album by the rock band Pink Floyd. The brick junctions are made of characters ...
59
votes
19answers
5k views

Cracking the Enigma?

Introduction The Enigma was one of the first electro-mechanical rotor cipher machines used in World War II. That means that after a single letter is coded, it would change the key for the next letter....
59
votes
44answers
4k views

Draw my downslashes

As a programmer, you've probably heard of forward slashes and backward slashes. But have you heard of downslashes? That's when you take a bunch of slashes, connect their ends and draw them going down. ...
59
votes
28answers
12k views

Why was 6 afraid of 7?

Why was 6 afraid of 7? Because 7 8 9! Given a string apply the following transformations: If there is a 6 next to a 7 remove the 6 (6 is afraid of 7) If the sequence "789" appears remove the 8 and ...
59
votes
13answers
4k views

Print a word clock

Since I saw the first one a few years ago, I always was subjugated by this kind of word clock where the time is actually spelled out by words being lit up or not into a meaningful sentence. The text ...
58
votes
16answers
5k views

De-Snakify a String

A regular string looks like this: Hello,IAmAStringSnake! And a string snake looks something like this: ...
57
votes
39answers
16k views

All Your Base Are Belong To Us (Restricted)

Input must not be required, and output must read "All your base are belong to us". Restrictions No external resources. Plus a minimum of two of the following: ...