Substrings or split methods in javascript

March 9, 2022

I have a simple problem that I think I need help with. So, I have a function that accepts a string in this format

"1. Crowe, Velvet (LoC), 2. Hume, Eleanor (Ext), 4. Shigure, Rokurou (DmN), 10. Mayvin, Magilou (MgC)" without the quotation marks.

Basically, a list of person’s names with rank number.

What I want is to split them such that I will get the ff result:

[
   "1. Crowe, Velvet (LoC)", 
   "2. Hume, Eleanor (Ext)", 
   "4. Shigure, Rokurou (DmN)",
   "10. Mayvin, Magilou (MgC)"
]

Is there a way to do that? I used split() method but it splits the string every time it sees an occurrence of the comma.

>Solution :

You could split using a regular expression /(?<=\)),\s/:

const str = "1. Crowe, Velvet (LoC), 2. Hume, Eleanor (Ext), 4. Shigure, Rokurou (DmN), 10. Mayvin, Magilou (MgC)";
const res = str.split(/(?<=\)),\s/);
console.log(res);

This will split on ), as suggested by cmgchess in the comments. The issue with splitting based on a string is that it removes some of the characters you want to keep. Instead, by using a regular expression, you can use (?<=\)) (here ?<= is called a positive lookbehind) to match and keep the ) in the resulting split element. The ,\s then splits based on a comma followed by a space (\s).

You could also use the following regex with .match() which is a little more robust, but may need to be updated depending on the text that can come after your number/rank:

/\d+\.\s\w+,\s\w+\s\(\w+\)/g

The above performs:

\d+\.: Will match one or more (+) digits followed by a dot
\s: Match a whitespace character
\w+,: Match one of more (+) word-characters (\w) followed by a comma ,
\s: Matches a space
\(\w+\): Match word characters surrounded by parentheses ( )
/g: Global flag to match the sequences for all occurrences in the string

const str = "1. Crowe, Velvet (LoC), 2. Hume, Eleanor (Ext), 4. Shigure, Rokurou (DmN), 10. Mayvin, Magilou (MgC)";
const res = str.match(/\d+\.\s\w+,\s\w+\s\(\w+\)/g);
console.log(res);