airwrk

problem1.js

function repeatDigitUntilOne(num) {
    while (num > 9) {
        num = num.toString().split('').reduce((sum, digit) => parseInt(sum) + parseInt(digit), 0)
    }
    return num;
}

console.log(repeatDigitUntilOne(38))
console.log(repeatDigitUntilOne(0))

problem2.js

function isDuplicate(nums) {
    const unique = {};
    let hasDuplicate = false

    nums.forEach(num => {
        if (unique[num]) {
            unique[num] += 1;
        }
        else {
            unique[num] = 1
        }
    });

    Object.keys(unique).forEach(each => {
        if (unique[each] > 1) {
            hasDuplicate = true
            return
        }
    })

    return hasDuplicate

}

console.log(isDuplicate([1, 2, 3, 4]))
console.log(isDuplicate([1, 2, 3, 1]))

problem3.js

function reverseVowel(string) {

    let vowel = ['a', 'e', 'i', 'o', 'u'];
    const trackVowelPosition = [];
    const strArr = string.split('');
    let vowelArr = [];
    let j = 0;

    for (let i = 0; i < strArr.length; i++) {
        if (vowel.includes(strArr[i].toLowerCase())) {
            trackVowelPosition.push(i);
            vowelArr.push(strArr[i]);
        }
    }

    vowelArr.reverse()
    trackVowelPosition.forEach(eachPosition => {
        strArr[eachPosition] = vowelArr[j];
        j++;
    })

    return strArr.join('')
}