HackerRank Day 7: Regular Expressions I 10 days of javascript solution

In this HackerRank Day 7: Regular Expressions I 10 days of javascript problem you need to Complete the function in the editor below by returning a RegExp object, re, that matches any string s that begins and ends with the same vowel. Recall that the English vowels are a, e, i, o, and u.

HackerRank Day 7: Regular Expressions I 10 days of javascript problem solution.

'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.trim().split('\n').map(string => {
        return string.trim();
    });
    
    main();    
});

function readLine() {
    return inputString[currentLine++];
}

function regexVar(str) {
//  ^ => first item matches:
// () => stores matching value captured within
// [aeiou] => matches any of the characters in the brackets
// . => matches any character:
// + => for 1 or more occurrances (this ensures str length > 3)
// \1 => matches to previously stored match. 
    // \2 looks for matched item stored 2 instances ago 
    // \3 looks for matched item stored 3 ago, etc

//  $ ensures that matched item is at end of the sequence

    let re = /^([aeiou]).+\1$/;
    return re;
}


function main() {
    const re = regexVar();
    const s = readLine();
    
    console.log(re.test(s));
}