Google sheets script (javascript) compare loop ignoring bottom 2 rows in spreadsheet

Question

I wrote a script that compares rows between two sheets and deletes all matching rows on the second sheet (named 'temp'). I set the loop to start at the end of temp and decrement, working toward the top. The script works but it ignores the bottom two rows on 'temp'...how can I fix this? I want to ensure it will delete the bottom two rows on temp when they match the data set from the other sheet.

I have confirmed that the bottom two rows are in fact duplicates and should be caught by the script and deleted.

Script:

function trimTempSheet() {

  var ss, s, s1, dt;
  var dirname='X DIR'
  var fs, f, fls, fl, name;
  var ncols=1,i, newRows, rw;

  ss=SpreadsheetApp.getActiveSpreadsheet();
  s=ss.getSheetByName('Report Results');

  name = 'temp';

  //Load current sheet to compare  
  var currentDataSet = s.getRange("A:S").getValues(); //Ignore final columns
  var newSheet = ss.getSheetByName(name);

 //Load imported data to compare
  var newData = newSheet.getRange("A:S").getValues();
  var headers = newData.shift();

//Create empty array to store data to be written [to add later]
    newRows=[];

//Compare data from newData with current data
  for(var i = newData.length-1; i > 0; --i) 
       { 

for(var j in currentDataSet)
  {
         if(newData[i].join() == currentDataSet[j].join()  )
    {
        newSheet.deleteRow(i);
     }
  }
          }

Answer 1

How about this modification?

From :

for(var i = newData.length-1; i > 0; --i)

To :

for(var i = newData.length-1; i >= 0; --i)

Note :

• About "the bottom two rows on 'temp'",
  • By above modification, one loop is added to the for loop.
  • In your script, the first element of newData is removed by var headers = newData.shift(); . By this, newData decreases one element.
    • For example, how about also removing this line?

If this modification was not useful for you, I'm sorry. At that time, can you show us your sample spreadsheet?

Answer 2

I do not know the optimal way to force the script to look at and delete the last row first, without skipping it. So I changed the delete line to "newSheet.deleteRow(i+1);"

Will this produce any unintended row deletes based on my iteration loops? I am not an expert at how google scripts handles arrays. I assume the loops will examine rows in newData (the sheet named 'temp) sequentially, from the last row to the first. In which case my solution would be acceptable. But I am not certain of this.