Copy formula to last row of column A (In Sheets ) - google-sheets

Question

I am very new to using macro's in google sheets, and struggling to replicate easy VBA codes
I am trying to find the last row of column A, then add formulas to various columns and copy down to the last row.
In VBA it is as simple as **("B2:B" & Lastrow).select
However, this is not so straight forward.
I have found and manipulated the following, however it always goes to the very last row rather than the last row of data
var sheetName = "Week 1";
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName(sheetName);
spreadsheet.getRange('E7').activate()
.setFormula('=iferror(if(match($B7,Names,0),VLOOKUP($B7,Special,3,false),0),0)');
var lr = sheet.getLastRow();
var fillDownRange = sheet.getRange(7, 5, lr-1);
sheet.getRange('e7').copyTo(fillDownRange);
What needs to be done to the above so that it only fills down to the last row of data in column A
All and any help greatly appreciated
EDIT-
I have update the code, (Obviously wrongly) and added to the s/sheet under tools, copy on tab
var sheetName = "Week 1";
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName(sheetName);
var lastRow = sheet.getLastRow();
var range = sheet.getRange("A7" + lastRow);
if (range.getValue() !== "") {
return lastRow;
} else {
return range.getNextDataCell(SpreadsheetApp.Direction.UP).getRow();
}
var lr = getLastDataRow(sheet,"A")
//Saturday Formula
spreadsheet.getRange('E7').activate()
.setFormula('=iferror(if(match($B7,Names,0),VLOOKUP($B7,Special,3,false),0),0)');
var fillDownRange = sheet.getRange(7, 5, lr-1);
sheet.getRange('E7').copyTo(fillDownRange);
as between these two rows is a light bulb sayingabout unreachable code, and everything after and including Var = lr** is greyed out
}
var lr = getLastDataRow(sheet,"A")

Answer 1

Correction of your first code
function myFunction() {
var sheetName = "Week 1";
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName(sheetName);
sheet.getRange('E7').setFormula('=iferror(if(match($B7,Names,0),VLOOKUP($B7,Special,3,false),0),0)');
var lr= sheet.getRange('A7').getNextDataCell(SpreadsheetApp.Direction.DOWN).getRow()
var fillDownRange = sheet.getRange(7, 5, lr-6,1);
sheet.getRange('E7').copyTo(fillDownRange);
}

Answer 2

Instead of var lr = sheet.getLastRow(); , try
lr = sheet.getRange('A1').getNextDataCell(SpreadsheetApp.Direction.DOWN).getRow()
change A by E if needed.
edit : Change A1 by A7 si A4 and A6 are empty.
If you have discontinous value, prefer
function getLastDataRow(sheet,col) {
// col in letter
var lastRow = sheet.getLastRow();
var range = sheet.getRange(col + lastRow);
if (range.getValue() !== "") {
return lastRow;
} else {
return range.getNextDataCell(SpreadsheetApp.Direction.UP).getRow();
}
}
and
lr = getLastDataRow(sheet,"A")