accessing spreadsheet by ID - google-apps-script

Question

I am using google Apps script.
I need to access some information in the spreadsheet.
I navigate to the file and find its ID.
However, the function
var fileID = file.getId()
var activityName = Sheets.Spreadsheets.Values.get (fileID,'B1:B4'); doesn't seem to accept the ID, even thought the ID is correct as I logged it and checked.
function getTheInformation() {
//navigate to the correct folder
var dApp = DriveApp;
var folderIter = dApp.getFoldersByName("scriptFolder");
var folder = folderIter.next();
//reality check
Logger.log(folder);
var filesIter = folder.getFiles();
var i = 1;
//cycle through the files
while (filesIter.hasNext())
{
var file = filesIter.next();
var fileID = file.getId()
var fileName = file.getName();
//here the code breaks
var activityName = Sheets.Spreadsheets.Values.get (fileID,'B1:B4');
i++;
Logger.log(fileName + " file ID " + fileID);
}
}

Answer 1

This worked for me:
function getTheInformation() {
var dApp = DriveApp;
var folderIter = dApp.getFoldersByName("Questions");
var folder = folderIter.next();
var filesIter = folder.getFiles();
while (filesIter.hasNext()) {
var file = filesIter.next();
var fileID = file.getId()
var fileName = file.getName();
if(fileName=='StackOverflow1') {
var values = Sheets.Spreadsheets.Values.get (fileID,'Sheet1!B1:B4')
Logger.log(values);
}
}
}
Things I did a little different: I added the sheet name to the range and I also checked for the correct file name.