Highly optimized merge for sorted arrays

mergeSorted.js

function mergeSorted(a,b){
    var alen = a.length
      , blen = b.length
      , i, j, k = j = i = 0
      , answer = new Array(alen + blen)
    ;//var

    while(i < alen && j < blen)
                    answer[k++] = a[i] < b[j] ? a[i++] : b[j++];
    while(i < alen) answer[k++] = a[i++];
    while(j < blen) answer[k++] = b[j++];

    return answer;
}