有没有办法避免这段代码中的嵌套循环？

function processData(data) {
    let result = [];
    for (let i = 0; i < data.length; i++) {
        result.push(processItem(data[i]));
    }
    return result;
}

function processItem(item) {
    let processedItem = [];
    for (let j = 0; j < item.length; j++) {
        processedItem.push(item[j] * 2);
    }
    return processedItem;
}

let data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
let result = data.map(item => item.map(num => num * 2));

let data = [
    { id: 1, value: 'a' },
    { id: 2, value: 'b' },
    { id: 3, value: 'c' }
];
let map = {};
data.forEach(item => {
    map[item.id] = item.value;
});
console.log(map[2]); // 输出 'b'

function processNestedArray(arr) {
    let result = [];
    arr.forEach(item => {
        if (Array.isArray(item)) {
            result.push(...processNestedArray(item));
        } else {
            result.push(item * 2);
        }
    });
    return result;
}
let data = [1, [2, [3, 4], 5], 6];
console.log(processNestedArray(data)); // 输出 [2, 4, 6, 8, 10, 12]

let data = [1, 2, 3, 4, 5, 6, 7, 8, 9];
data.sort((a, b) => a - b);
let index = binarySearch(data, 5);
console.log(index); // 输出 4

function binarySearch(arr, target) {
    let left = 0;
    let right = arr.length - 1;
    while (left <= right) {
        let mid = Math.floor((left + right) / 2);
        if (arr[mid] === target) {
            return mid;
        } else if (arr[mid] < target) {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    return -1;
}