Check if Column Contains a Value - google-apps-script

Question

What do I add to the if statement to check if Column 5 in the applicable row contains a value and prevent the setValue() from overriding the old value?
function onEdit(e) {
var sheet = e.source.getActiveSheet();
var i = ['Sheet1', 'Sheet2'].indexOf(sheet.getName());
if (e.range.getValue() != '' && i > -1 && e.range.columnStart === 1) {
e.range.offset(0,4).setValue(Utilities.formatDate(new Date(), "GMT-8", "MM/dd/yyyy"));
}
}

Answer 1

Explanation:
Add a condition in the if statement for column 5 to be empty at row in order to fill it:
sheet.getRange(row,5).getValue()==''
Solution:
function onEdit(e) {
var sheet = e.source.getActiveSheet();
var row = e.range.getRow();
var i = ['Sheet1', 'Sheet2'].indexOf(sheet.getName());
if (e.range.getValue() != '' && i > -1 && e.range.columnStart === 1 && sheet.getRange(row,5).getValue()=='') {
e.range.offset(0,4).setValue(Utilities.formatDate(new Date(), "GMT-8", "MM/dd/yyyy"));
}
}
Or:
I formatted your code a little bit to make it more compact:
function onEdit(e) {
const sheet = e.source.getActiveSheet();
const row = e.range.getRow();
const col = e.range.getColumn();
const sheets = ['Sheet1', 'Sheet2'];
if (e.range.getValue() != '' && sheets.includes(sheet.getName())
&& col === 1 && sheet.getRange(row,5).getValue()==''){
e.range.offset(0,4).setValue(Utilities.formatDate(new Date(), "GMT-8", "MM/dd/yyyy"));
}
}