What is the type of e.values and e.oldValues, when reading boolean values?

Reading differents boolean types of e.values of checkboxes on a sheet, I resumed the (odd) e.values read on a table.)

I got this values by clicking on checkboxes and triggering onEdit function. the values read are not boolean. in the table, you can see that the values read are TRUE/FALSE and string type. Reading the cell by his coordinates , it return the correct values as you can see in this other table.

you can test with this code

    function onEdit(e) {
      var eA1 = e.range.getA1Notation();
      var ui = SpreadsheetApp.getUi();

      // e.value and his typeof
      ui.alert("(" + eA1 + ") e.value=" + e.value);
      ui.alert("(" + eA1 + ") typeof e.value=" + typeof e.value);

      // eValue and his typeof
      var eValue=e.value;
      ui.alert("reading of  eValue......");
      ui.alert("(" + eA1 + ") eValue=" + eValue);
      ui.alert("(" + eA1 + ") typeof eValue=" + typeof eValue);

      // getting de value of (e)cell
      var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
      var eTargetCell = sheet.getRange(eA1);
      var eCellValue = eTargetCell.getValue();

      // eCellValue and his typeof
      ui.alert("direct reading of cell.......");
      ui.alert("(" + eA1 + ") eValue=" + eCellValue);
      ui.alert("(" + eA1 + ") typeof eValue=" + typeof eCellValue);
    }

You can easily make a function to get the boolean value of 'e' cell. To get the correct value of e.oldValue... you can recover it in the original cell, if needed, easily by

    e.range.setValue(eOldValue);
...

or in another cell(not tested this point)


I have not found help of this issue on internet, and I expend many hours drilling, I hope this can save time to others, or maybe someone can modify this code to do a better version.