Largest Number At Least Twice of Others

LeetCode題目: 747. Largest Number At Least Twice of Others

My solution:

/**
 * @param {number[]} nums
 * @return {number}
 */
let dominantIndex = nums => {
    const sortArrays = nums.map((item, idx) => [idx, item]).sort((a, b) => a[1] - b[1]);
    return sortArrays.at(-2)[1] * 2 <= sortArrays.at(-1)[1] ? sortArrays.at(-1)[0] : -1;
};