All in one function for transforming word casings

  • casex

Downloads in past


10603.0.28 months ago5 years agoMinified + gzip package size for casex in KB


Casex is now part of DXTR.DEV
I (Pedro) am migrating several of my packages to my new company DXTR.DEV, where I'll ship tools and apps that improve developer experience.
Besides being moved, Casex now has Typescript types and a new function signature with named exports.
New GitHub repo:
NPM package:


Previous versions

Although for most cases it will work just fine, casex 3.x is not fully compatible previous versions. If you need previous docs please refer to:


šŸ“¦ 343B gziped
npm install --save casex



import casex from 'casex';

casex(text, pattern);
casex('john doe', 'Ca Se'); // John Doe

How it works

  1. Breaking text into words

By default, casex uses capitalizations (A-Z), -, _ and spaces (\s) to break the text into words.
Let's take for example i_am the-real JohnDoe:
  • i: 1st word
  • am: 2nd+ word
  • the: 2nd+ word
  • real: 2nd+ word
  • John: 2nd+ word
  • Doe: 2nd+ word

1.1 Custom delimiters

The default will likely work for most of your cases, but if you wish, you can provide custom delimiters:
casex(',baz', 'Ca Se', '.,'); // Foo Bar Baz

Note: The default delimiters are: A-Z\\s_-.

  1. Applying capitalization pattern and gluing words together

Let's take for example Ca_se:
  • C: first letter of the first word
  • a: second and subsequent letters of the first word
  • _: anything between the first two and last two letters is glue and will be repeted between words
  • s: first letter of the second and subsequent words
  • e: second and subsequent letters of the second and subsequent words

Confusing? Check out the demo
and/or examples below. I'm sure you'll get the hang of it :)
Note: You could use any other letters to describe, such as aa$aa or na_me. What matters is that it takes the first two and last two letters for checking capitalization and whatever is in the middle is "glue".

2.1 Special transformations

Besides using lower and uppercase letters, you can also use:
  • *: Do not change word
  • -: Remove word


For these examples I'll use the text i_am the-real JohnDoe
  • Pattern: case
  • Output: iamtherealjohndoe

  • Pattern: CASE

  • Pattern: case
  • Output: i
  • Pattern: ca-se
  • Output: i-am-the-real-john-doe

  • Pattern: caSe
  • Output: iAmTheRealJohnDoe

  • Pattern: CaSe
  • Output: IAmTheRealJohnDoe

Sentence case
  • Pattern: Ca se
  • Output: I am the real john doe

Title Case
  • Pattern: Ca Se
  • Output: I Am The Real John Doe

Weird Example
  • Pattern: Ca12 34Se
  • Output: I12 34Am12 34The12 34Real12 34John12 34Doe

Examples with special characters

Capitalize first letter
  • Pattern: C\* \*\
  • Output: I am the real John Doe

  • Input: John Doe
  • Pattern: C-S-
  • Output: JD