Javascript - How to split a string into a nested array?

Question

I know I can use split function to transform a string to an array but how can a string be split twice to produce a nested array?

I expected this would be sufficent but it does not produce the desired output.

var myString = "A,B,C,D|1,2,3,4|w,x,y,z|"
var item = myString.split("|");
var array = [item.split(",")];

Would it be more optimal to use a for each loop?

EXPECTED OUTPUT

var array = [
 ["A","B","C","D"],
 ["1","2","3","4"],
 ["w","x","y","z"],
];

• Dave Newton: I mean, it would certainly be workier since the current code makes no sense.

Answer 1

Once you've split on |, use .map to account for the nesting before calling .split again. There's also an empty space after the last |, so to exclude that, filter by Boolean first:

const myString = "A,B,C,D|1,2,3,4|w,x,y,z|";
const arr = myString
 .split('|')
 .filter(Boolean)
 .map(substr => substr.split(','));
console.log(arr);

Or you could use a regular expression to match anything but a |:

const myString = "A,B,C,D|1,2,3,4|w,x,y,z|";
const arr = myString
 .match(/[^|]+/g)
 .map(substr => substr.split(','));
console.log(arr);

Answer 2

var myString = "A,B,C,D|1,2,3,4|w,x,y,z"
var item = myString.split("|");
var outputArr = item.map(elem => elem.split(","));
console.log(outputArr);

• Dave Newton: Why map if you’re just going to use it to iterate?
• Darshana Pathum: oops. I saw that. I have't edit the answer before I post. Thank you. I wll update