Script to validate if value exists in a list - google-apps-script

Question

I have a google spreadsheet which will be used for collaboration and I was able to create a UI interface which will fetch and update data from a table to make it easier for users.
For the work I need to restrict users to only be able to update rows if they are assigned to them and I am able to do it. But along with that, I also need to allow administrator to assign or update rows which are not assigned to them.
I have a table with all employee's email address and an admin flag for those who are admin.
Name____________Email________________Is Admin
Employee 1_______emp1#domain.com_____Admin
Employee 2_______emp2#domain.com_____
Employee 3_______emp3#domain.com_____
Employee 4_______emp4#domain.com_____Admin
Employee 5_______emp5#domain.com_____
Employee 6_______emp6#domain.com_____
How can I write a something in my script that will allow me to if the user who is triggering a function has admin right or not.
I user Session.getActiveUser().getEmail() to pull out the users email address. I am creating the tool to be used within google apps domain.
Code that checks if the user is the owner of the row, this part works fine but what I want to do is if a user is admin they basically will skip this check.
if (s.getRange("E4").getValue() != usr()){
msg("Once a Task is assigned to an employee, only assigned employee can make any changes to the Task. Thank you");
return;
}
s = sheet
usr() = function calling to check active user email
If I can do something like countifs where I can check count based on the email address and Admin criteria and if its >= 1 proceed if its 0 show error that you can not make changes.
Please let me know.
Really appreciate the help.
Thank you.
Zooooon

Answer 1

Are you looking for something like this?
function myFunction() {
var s = SpreadsheetApp.getActiveSheet();
var usr = Session.getActiveUser().getEmail();
var emails = s.getRange("E2:F").getValues();
for (var i=0;i<emails.length;i++) {
if (emails[i][0] === usr){
if (emails[i][1] === "Admin") {
//Do something when Admin
return;
} else {
//Do something when not admin
return;
}
} else {
//Do something when email not in the list
}
}
}
I am assuming your data is in the range "D:F"