remove multible years from array

Hi I am creating an array with 10 other arrays using concat. The array is a list of different years. The multiple arrays is creating multiple years for example 2 1998's. How do I only display 1 of each year in my table view. Here is a sample:

alldata = data0.concat (data1, data2, data3, data4, data5, data6, data7, data8, data9, data10, data11, data12, data13, data14, data15);
 
//sort data by name
alldata.sort(sortByRDate);
 
//done sort data
function sortByRDate(a, b) {
   var x = a.RDate;
    var y = b.RDate;
   return ((x < y) ? -1 : ((x > y) ? 1 : 0));
}
 
//done sort data
 
//Rdate data to table   
tableview.setData(alldata2);

This works but displays multiples of the same year, I would only like to show 1 of each year.

Use a javascript object as a hash array. After you concatenate the arrays, make a pass through the years to filter out the unique years. Then put those values back into the alldata array:

var unique_years = {};
 
var i;
for (i = 0; i < alldata.length; i++)
{
    var year = alldata[i];
    unique_years[year] = 1;
}
 
alldata = [];
for (var y in unique_years)
{
    alldata.push (y);
}?

Simply add a unique function to you array objects.

Add the function to the Array JavaScript object

Array.prototype.unique = function(){
  return this.filter(function(s, i, a){
    return i == a.lastIndexOf(s);
  });
}

Then use it on your big array

tableview.setData(alldata.unique());