apps script - search value from sheet1 in array in sheet2 (google sheets) - google-apps-script

Question

I'm completely new to apps script and java.
I have a tracker where users insert IDs in col1 sheet1. I need to be able to prevent and alert them whenever their input DOESN'T exists in an array in col2 sheet 2.
so far I've got this, but this is not working for me at all.
var ss = SpreadsheetApp.getActiveSpreadsheet();
function onEdit(e) {
var sheet = ss.getSheetByName("Sheet1")
var so = ss.getSheetByName("Sheet2"); so.activate();
var vltest = sheet.getActiveCell().getValue()
var vlary = so.getActiveCell().getValue()
var r = sheet.getActiveRange().getRow()
var c = sheet.getActiveRange().getColumn();
if(vltest!=="" && c==1 && r>1 && sheet == "Sheet1"){
var data = so.getRange("B1:B").getValues().filter(String).flat()
if(data.indexOf(vlary)=data.lastIndexOf(vlary)){
e.range.setValue("")}
if(data.indexOf(vlary)=data.lastIndexOf(vlary)){SpreadsheetApp.getUi().alert("Alert", "Alert", SpreadsheetApp.getUi().ButtonSet.OK);}}}
Any ideas?

Answer 1

You need to get all values from compare sheet, loop them through and look for match of the value, that onEdit() gives you back. Something like this:
function onEdit(e) {
var ss = SpreadsheetApp.openById('sheet_ID'); //or getActive();
var so = ss.getSheetByName("Sheet2");
// let's say you get all rows from column 1
var compareData = so.getRange(1, 1, so.getLastRow(), 1).getValues();
for (var d = 0; d < compareData.length; d++) {
if (compareData[d] === e.value) {
SpreadsheetApp.getUi().alert("Alert", "Alert", SpreadsheetApp.getUi().ButtonSet.OK)
}
}