How to use map object In Javascript

Using Nested loop (Brute force Approach)

This approach uses more optimized `Map` data structure to store cumulative sums and their corresponding indices. It efficiently finds the length of the longest subarray with a zero sum within the given array by updating the maximum length based on the difference between current and previously encountered sum indices.

Example: To demonstrate finding the longest subarray with zero sum using map method in JavaScript.

Javascript


                    function answer(arr) {
    let maxLength = 0;
    let sumIndexMap = new Map();
    let sum = 0;

    for (let i = 0; i < arr.length; i++) {
        sum += arr[i];

        if (sum === 0) {
            maxLength = i + 1;
        } else if (sumIndexMap.has(sum)) {
            maxLength = Math
                .max(maxLength, i - sumIndexMap.get(sum));
        } else {
            sumIndexMap.set(sum, i);
        }
    }

    return maxLength;
}

let arr = [3, 2, -5, 3, -3, -4];
console.log(answer(arr));