Google Apps Script For Loop Through Array Speed - arrays

Question

I have a simple example of a function I am working on. I am trying to loop through a column of unique item IDs. If the item ID is found in the item ID column of another sheet, it pulls adjacent attributes from the data table, and assigns them in the same row. I have a function and it works, however, this is a base example. In reality I need to do this for 1000+ rows, and much larger data sets. It is currently taking 30-60 mins to run. I believe there is a much faster way to do this with arrays and using foreach and getvalues I'm just not sure how to get started. Any help would be greatly appreciated.
function example() {
var list = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("List");
var data = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Data")
var listendRow = list.getLastRow();
var dataendRow = data.getLastRow();
var dataid = data.getDataRange().getValue();
for (var i = 2; i <= listendRow; i++) {
for (var j = 2; j <= dataendRow; j++){
var idnum = [list.getRange(i, 2,listendRow).getValue()];
var id = data.getRange(j, 3).getValue();
var name = data.getRange(j, 4).getValue();
var weight = data.getRange(j, 5).getValue();
if (idnum == id){
list.getRange(i, 3).setValue(name);
list.getRange(i, 4).setValue(weight);
}
}
}
}
Here is the link to the sheet:
https://docs.google.com/spreadsheets/d/1PPZKRXhiAAfFG1d-CU02MV_CSrqbdsCsyo_QADz5yiA/edit?usp=sharing

Answer 1

I believe your goal is as follows.
Your script works fine. Under this condition, you want to reduce the process cost of your script.
Modification points:
When I saw your sample Spreadsheet, V8 runtime is not used. Please enable V8 runtime. When V8 runtime is used, the process cost of the script can be reduced.
In your script, getValue and setValue are used in a loop. In this case, the process cost becomes high. Ref
SpreadsheetApp.getActiveSpreadsheet() can be declared one time.
In order to reduce the process cost of your script, how about the following modification?
Modified script:
Before you run this script, please enable V8 runtime.
function example2() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var list = ss.getSheetByName("List");
var data = ss.getSheetByName("Data");
var obj = data.getRange("C2:E" + data.getLastRow()).getValues().reduce((o, [a, ...b]) => (o[a] = b, o), {});
var range = list.getRange("B2:B" + list.getLastRow());
var values = range.getValues().map(([b]) => obj[b] || [null, null]);
range.offset(0, 1, values.length, 2).setValues(values);
}
When this script is run, the values are retrieved from "Data" sheet and create an object for searching the ID. And, the values are retrieved from "List" sheet and an array for putting to the sheet is created. And also, the array is put to "List" sheet.
Note:
When you try to use this script without enabling V8 runtime, an error like Syntax error occurs. Please be careful about this.
This modified script is for your sample Spreadsheet. If your actual Spreadsheet is differnt structure from your provided sample one, this modified script might not be able to be used. Please be careful about this.
If you cannot use V8 runtime, please test the following modified script.
function example2b() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var list = ss.getSheetByName("List");
var data = ss.getSheetByName("Data");
var obj = data.getRange("C2:E" + data.getLastRow()).getValues()
.reduce(function (o, [a, b, c]) {
o[a] = [b, c];
return o
}, {});
var range = list.getRange("B2:B" + list.getLastRow());
var values = range.getValues().map(function ([b]) { return obj[b] || [null, null] });
range.offset(0, 1, values.length, 2).setValues(values);
}
References:
getValues()
setValues(values)
reduce()
map()