how to sort a 2D array in google apps script/ google spreadsheet
<p>I have a google spreadsheet which contains the multiple data spread across various columns (like 6 columns - Phone number, IMEI, URL, Id, Reg No and Time) and i have 15K rows of data.</p>

<p>I have to find/show all the duplicate phone number(Column 0) and data associated with them in a new sheet.</p>

<p>However when i try to sort the data, it throws me error like</p>

<p>"Comparison method violates its general contract. (line 6, file "Code")" </p>

<p>The code is shown below for your reference:</p>

<pre><code>function myFunction() {

  var values  = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('DUP').getDataRange().getValues()

  var dupData = new Array();

  values.sort(function sortFunction(a, b) {
    if (a[0] === b[0]) {
        return 0;
    }
    else {
        return (a[0] &lt; b[0]) ? -1 : 1;
    }
});

  for(i=1;i&lt;values.length;i++)
  {
    if (values[i][0] == values[i+1][0]) {
        dup.push(values[i]);
    }
  }

   var new1 = dpnum.getSheetByName('Test123');
  new1.getRange(1,1,dup.length,dup[0].length).setValues(dup);

}
</code></pre>