---
title: Spinal Tap Case
---
 Remember to use <a>**`Read-Search-Ask`**</a> if you get stuck. Try to pair program  and write your own code 
###  Problem Explanation:
Convert the given string to a lowercase sentence with words joined by dashes.
#### Relevant Links
* <a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String' target='_blank' rel='nofollow'>String global object</a>
* <a href='https://guide.freecodecamp.org/javascript/regular-expressions-reference/' target='_blank' rel='nofollow'>JS Regex Resources</a>
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-replace/15942' target='_blank' rel='nofollow'>JS String Prototype Replace</a>
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-tolowercase/15948' target='_blank' rel='nofollow'>JS String Prototype ToLowerCase</a>
##  Hint: 1
Create a regular expression for all white spaces and underscores.
> _try to solve the problem now_
##  Hint: 2
You will also have to make everything lowercase.
> _try to solve the problem now_
##  Hint: 3
The tricky part is getting the regular expression part to work, once you do that then just turn the uppercase to lowercase and replace spaces with underscores using `replace()`.
> _try to solve the problem now_
## Spoiler Alert!
**Solution ahead!**
##  Basic Code Solution:
function spinalCase(str) {
// Create a variable for the white space and underscores.
var regex = /\s+|_+/g;
// Replace low-upper case to low-space-uppercase
str = str.replace(/([a-z])([A-Z])/g, '$1 $2');
// Replace space and underscore with -
return str.replace(regex, '-').toLowerCase();
}
// test here
spinalCase('This Is Spinal Tap');
 <a href='https://repl.it/CLnS/0' target='_blank' rel='nofollow'>Run Code</a>
### Code Explanation:
* **regex** contains the regular expression `/\s+|_+/g`, which will select all white spaces and underscores.
* The first `replace()` puts a space before any encountered uppercase characters in the string **str** so that the spaces can be replaced by dashes later on.
* While returning the string, another `replace()` replaces spaces and underscores with dashes using **regex**.
##  Intermediate Code Solution:
function spinalCase(str) {
// Replace low-upper case to low-space-uppercase
str = str.replace(/([a-z])([A-Z])/g, '$1 $2');
// Split on whitespace and underscores and join with dash
return str.toLowerCase().split(/(?:_| )+/) .join('-');
}
// test here
spinalCase('This Is Spinal Tap');
 <a href='https://repl.it/CLnT/0' target='_blank' rel='nofollow'>Run Code</a>
### Code Explanation:
* Similar to the first solution, the first `replace()` puts a space before any encountered uppercase characters in the string **str** so that the spaces can be replaced by dashes later on.
* Instead of using `replace()` here to replace whitespace and underscores with dashes, the string is `split()` on the regular expression `/(?:_| )+/` and `join()`-ed on `-`.
#### Relevant Links
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-split/15944' target='_blank' rel='nofollow'>JS String Prototype Split</a>
* <a href='http://forum.freecodecamp.com/t/javascript-array-prototype-join/14292' target='_blank' rel='nofollow'>JS Array Prototype Join</a>
##  Advanced Code Solution:
function spinalCase(str) {
// "It's such a fine line between stupid, and clever."
// --David St. Hubbins
return str.split(/\s|_|(?=[A-Z])/).join('-').toLowerCase()
}
 <a href='https://repl.it/EUZV' target='_blank' rel='nofollow'>Run Code</a>
### Code Explanation:
* Split the string at one of the following conditions (_converted to an array_)
* a whitespace character [`\s`] is encountered
* underscore character [`_`] is encountered
* or is followed by an uppercase letter [`(?=[A-Z])`]
* Join the array using a hyphen (`-`)
* Lowercase the whole resulting string
#### Relevant Links
* <a href='http://devdocs.io/javascript/global_objects/string/split' target='_blank' rel='nofollow'>String#split</a>
* <a href='http://devdocs.io/javascript/global_objects/regexp' target='_blank' rel='nofollow'>RegExp</a>
* <a href='http://devdocs.io/javascript/global_objects/array/join' target='_blank' rel='nofollow'>Arrray#join</a>
* <a href='http://devdocs.io/javascript/global_objects/string/tolowercase' target='_blank' rel='nofollow'>String#toLowerCase</a>
##  NOTES FOR CONTRIBUTIONS:
*  **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
* Add an explanation of your solution.
* Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. 