Iterate through named range and update values - google-apps-script

Question

I need to iterate through a named range in Google Sheet and update the value based on other named ranges.
I have this now and I'm getting an error on line 13
function onEdit(e) {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var FreeCopiesTarget = ss.getRangeByName('FreeCopiesTarget');
var CostPerCopy = ss.getRangeByName('CostPerCopy');
var FreeCopies = ss.getRangeByName('FreeCopies');
var values = FreeCopiesTarget.getValues();
for (var counter = 0; counter <= 4; counter++) {
var cost = CostPerCopy.getValues()[counter][0] * FreeCopies.getValues()[counter][0];
var r = FreeCopiesTarget.getValues()[counter][0];
r.setValue(cost);
}
}
Any help is appreciated.

Answer 1

Issue:
r is a value from a cell, which can be a Number, Boolean, String, or a Date. None of these includes the method setValue. r should be a Range instead.
Code sample:
function onEdit(e) {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var FreeCopiesTarget = ss.getRangeByName('FreeCopiesTarget');
freeCopiesValues = FreeCopiesTarget.getValues();
var CostPerCopy = ss.getRangeByName('CostPerCopy').getValues();
var FreeCopies = ss.getRangeByName('FreeCopies').getValues();
for (var counter = 0; counter <= 4; counter++) {
var cost = CostPerCopy[0][counter] * FreeCopies[0][counter];
freeCopiesValues[0][counter] = cost;
}
FreeCopiesTarget.setValues(freeCopiesValues);
}
Note:
It's not best practice to use getValues iteratively. It's preferrable to get all values at once and work with the resulting 2D array, as shown in the sample above.

Answer 2

Following Iamblichus answer, I tweaked as follows and it works as expected.
function onEdit() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var FreeCopiesTarget = ss.getRangeByName('FreeCopiesTarget');
freeCopiesValues = FreeCopiesTarget.getValues();
var CostPerCopy = ss.getRangeByName('CostPerCopy').getValues();
var FreeCopies = ss.getRangeByName('FreeCopies').getValues();
for (var counter = 0; counter <= 4; counter++) {
var cost = CostPerCopy[0][counter] * FreeCopies[0][counter];
freeCopiesValues[0][counter] = cost;
}
FreeCopiesTarget.setValues(freeCopiesValues);
}