flattenArray.js

flattenArray.js

function flattenArray(array) {
    let temp = [];
    
    function flatten(arr) {
        if (Array.isArray(arr)) {
            const [head, tail] = [arr[0], arr.slice(1)]
            
            flatten(head);
            
            if (tail.length > 0) flatten(tail);
        } else {
            temp.push(arr);
        }
    }
    
    flatten(array);
    
    return temp;
}