Creating and populating an array with a fixed width in JavaScript

My solution uses two arrays and two maps with plenty of possibilities for optimizations. Here's a rough sketch:

1. Sort your array by jobID. (let's call this the "jobList")

2. Keep a "map" that is keyed on unique timestamps. ("timeStampMap"). The map should contain one entry for each unique timestamp.

3. Keep another array of unique timestamps and sort it. ("timeList")

4. Each item in the "timeStampMap" keeps another map of jobs on that timestamp value

5. Iterate over each value in the timestamp list.

   Within each iteration, iterate over each job in the jobList. if the job is in the corresponding timestamp map output job.completionTime

   otherwise, output zero.

There are two possible optimizations to the code I show below. 1. You could likely use the input array as the "jobList" without having to copy it. 2. You could likely combine the map of maps into one large map.

function jobSorter(a,b) {
    return a.jobID - b.jobID;
}

function numberSort(a,b) {
    return a - b;
}


function buildSortedArray(yourArray) {

    var index, j, item;
    var jobList = []; // array of {jobID, timeStamp, timeComp};
    var timeStampMap = {};
    var timeStampList = [];
    var key, jobkey;
    var output = [];

    // loop through every item in the array
    for (index = 0; index < yourArray.length; index++) {
        item = yourArray[index];         

        // push each item into a "job list"
        job = {jobID: item[1], timeStamp: item[0], timeComp: item[2]};
        jobList.push(job);

        // now use both a map and a list to keep track of all the unique timestamps
        key = "$timestamp$" + job.timeStamp.toString();

        if (timeStampMap[key] === undefined) {
            timeStampMap[key] = {};
            timeStampMap[key].jobMap = {};

            timeStampList.push(job.timeStamp); // keep another timestamp array that we can sort on
        }

        // add this job to the timestamp
        jobkey = "$jobid$" + job.jobID.toString();
        timeStampMap[key].jobMap[jobkey] = job;
    }

    // let's do some sorting
    timeStampList.sort(numberSort); // timeStampList is now in ascending order
    jobList.Sort(jobSorter);        // jobList is now in ascending order


    for (index = 0; index < timeStampList.length; index++) {
        item = [];

        item.push(timeStampList[index]);
        for (j = 0; j < jobList.length; j++) {

            key = "$timestamp$" + timeStampList[index].toString();
            jobkey = "$jobid$"  + jobList[j].toString();

            if (timeStampMap[key].jobMap[jobkey]) {
                item.push(timeStampMap[key].jobMap[jobkey].timeComp);
            }
            else {
              item.push(0);
            }
        }

        output.push(item);
    }


    return output;
}