a!localVariables(

local!words: { "Apple", "Sky", "Orange", "Fly" },

a!forEach(

items: local!words,

expression: a!localVariables(

local!word: fv!item,

{

word: local!word,

vowels: reject(

fn!isnull,

a!forEach(

items: enumerate(len(local!word)) + 1,

expression: a!localVariables(

local!char: mid(local!word, fv!item, 1),

if(

contains(

{

"a",

"e",

"i",

"o",

"u",

"A",

"E",

"I",

"O",

"U"

local!char

local!char,

null

)

}

)

How it works step-by-step:

Outer Loop (a!forEach): Iterates through each word in the local!words array ("Apple", "Sky", etc.).
Character Splitting: enumerate(len(local!word)) + 1 generates a sequence of numbers from 1 to the length of the current word. The mid() function uses these numbers to extract each character one by one.
Vowel Checking: The if() and contains() functions check if each extracted character matches a predefined list of uppercase or lowercase vowels. Non-vowels are replaced with null.
Cleanup (reject): The reject(fn!isnull, ...) function filters out all the null entries, leaving a clean list of only the vowels found in that word.