qualfirst.js

function deepSearch(arr, element) {
    if (typeof arr != 'number') {
        for (var i = 0; i < arr.length; i++) {
            result = deepSearch(arr[i], element);
            if (result) {
                return true;
            }
        }
        return false;
    } else {
        if (arr == element) {
            return true;
        }
    }
}

console.log(deepSearch([1, 2, [3, 7, [22, [23]], 4, 5], 17], 7));