Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Challenges

Post History

75%
+4 −0
Challenges Single letter HTML

Indicate whether a letter is an HTML element. Input A single lowercase letter. Output An indication of whether the input is a standard HTML element. This could be one of 2 distinct value...

10 answers  ·  posted 6mo ago by trichoplax‭  ·  last activity 3mo ago by forestbeasts‭

Question code-golf string html
#1: Initial revision by user avatar trichoplax‭ · 2026-03-12T14:13:02Z (6 months ago)
Single letter HTML
Indicate whether a letter is an HTML element.

## Input

- A single lowercase letter.

## Output

- An indication of whether the input is a standard HTML element.
- This could be one of 2 distinct values to indicate true or false, or any truthy or falsy value if your programming language supports that.
- You may choose whether truthy or falsy indicates an HTML element.

## Test cases 

Test cases are in the format `input : output`.

These are correct at time of posting, and will remain the measure of validity for answers to this challenge even if the HTML specification changes in future.

```txt
a : true
b : true
c : false
d : false
e : false
f : false
g : false
h : false
i : true
j : false
k : false
l : false
m : false
n : false
o : false
p : true
q : true
r : false
s : false
t : false
u : false
v : false
w : false
x : false
y : false
z : false
```

## Scoring
This is a [code golf challenge]. Your score is the number of bytes in your code.

> Explanations are optional, but I'm more likely to upvote answers that have one.


[code golf challenge]: https://codegolf.codidact.com/categories/49/tags/4274 "The code-golf tag"