Question

How to iterate an array from the middle outward (stepping left and right alternately) in JavaScript

Answer 1

const arr = [0, 1, 2, 3, 4, 5, 6, 7];
const n = arr.length;

// Middle index for even-sized arrays
const mid = Math.floor(n / 2);

// Left starts before the middle, right starts at the middle
let left = mid - 1;
let right = mid;

// Iterate outward from the middle
while (left >= 0 || right < n) {

    if (right < n) {
        console.log(arr[right]);
        right++;
    }

    if (left >= 0) {
        console.log(arr[left]);
        left--;
    }
}



/*
run:

4
3
5
2
6
1
7
0

*/

 

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