Compare data with present date google script

Question

Hi i want to compare column with date (i.e "Referral Date" column) with present day , here is what i have

function newF(){
var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Worksheet');
var range = ss.getDataRange();
  var headers = range.getValues()[0];
  var colIndex = headers.indexOf("Referral Date");
  var today = new Date();
var searchRange = ss.getRange(2,colIndex+1,ss.getLastRow()-1);
for (i=0;i<range.getLastRow();i++){
  var dates = searchRange.getValues();
      if (today.valueOf()>dates.valueOf()){
        updatelFilter()
      } else{
        SpreadsheetApp.getUi().alert('Future Date Error');
      break;
    }
  }
}

The problem i have is, it throws alert Future Date Error irrespective of date in column (Referral Date). Let me know if additional information is required.

My goal:

1)if date column (Referral Date) is greater than present date : Throw alert error & should not run updateFilter

2)if (Referral Date) is lesser than present date: Run updateFilter function

Answer 1

Issues

1. searchRange.getValues() yields a two dimensional array. So dates[0][0] points to a date, while dates[0] points to an array.
2. var dates = searchRange.getValues(); is being called inside the loop repeatedly, when it should ideally be called outside once since the value will not change; calling it inside the loop is costly and redundant
3. for (i=0;i<range.getLastRow();i++){ the condition can be replaced with i<dates.length if point 2 is followed
4. if (today.valueOf()>dates.valueOf()){ I believe is supposed to have dates[0] instead

Modified Code

function newF(){
  var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Worksheet');
  var range = ss.getDataRange();
  var headers = range.getValues()[0];
  var colIndex = headers.indexOf("Referral Date");
  var today = new Date();
  var searchRange = ss.getRange(2,colIndex+1,ss.getLastRow()-1);
  var dates = searchRange.getValues().map(d=>d[0]); 

  for (i=0;i<dates.length;i++) {
    if (today.valueOf()>dates[i].valueOf()){
      updateFilter()
    } else {
      SpreadsheetApp.getUi().alert('Future Date Error');
      break;
    }
  }
}

To run updateFilter only if no future dates

Replace the loop with the following -

if(dates.some(d => today.valueOf() < d.valueOf())) {
  SpreadsheetApp.getUi().alert('Future Date Error');
} else {

  for (let i=0; i<dates.length; i++) {
    updateFilter();
  }
}