getReversed - A solution to one of the problems on meet.js Warsaw

getReversed.js

function getReversed (str) {
    var i, idx, result = [];
    for (i = 0; i < str.length; ++i) {
        idx = (i % 2) ? (str.length - Math.ceil((i + 1) / 2)) : Math.ceil(i / 2);
        result.push(str[idx]);
    }
    return result.join('');
}