How to set number format for each value from single column in Google Sheets depends from value?

Question

I got an array in a single column. I need to reduce fractional part for big numbers like >= 1, keep 1 symbol of fractional part for numbers <1 and >=0,1, keep 2 symbols of fractional part for numbers <0,1 and >=0,01, keep 3 symbols of fractional part for numbers <0,01 and >=0,001. All values can not be rounded, for user view only. For example:

[33800]->33800; 
[468]->468;
[]-> "";
[1170.0000000000002]->1170; 
[2437.5]->2437; 
[2762.5]->2762; 
[322.4]->322; 
[1430.0000000000002]->1430; 
[910]->910; 
[1300]->1300; 
[52]->52; 
[0.023]->0,023; 
[6500]->6500.

I tried to do that but my way is wrong

function recalculate() {
  const sh = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  const sourceValues = sh.getRange(1, 1, sh.getLastRow()).getValues();
  const ratio = sh.getRange(1, 2, sh.getLastRow()).getValues();

  const targetRange = sh.getRange(1, 3, sh.getLastRow());
  let result = [];
  for (let i = 0; i < sourceValues.length; i++){
    result.push([sourceValues[i] * (1 - ratio[i])])
    }
  console.log(result)
  let numFormat = targetRange.setValues(result);
  for (i = 0; i < numFormat.length; i++){
    switch (numFormat[i] > 0) {
      case numFormat < 0.1:
        numFormat[i].setNumberFormat('#,##0.00')
        ;
      case numFormat < 1:
        numFormat[i].setNumberFormat('#,#0.0')
        ;
      default: numFormat[i].setNumberFormat('#0');
      }
  }   
  
}

Can you explain why and where I'm wrong?

Modified script

function recalculate() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sh = ss.getActiveSheet();
  const sourceValues = sh.getRange(1, 1, sh.getLastRow()).getValues();
  const ratio = sh.getRange(1, 2, sh.getLastRow()).getValues();
  const targetRange = sh.getRange(1, 3, sh.getLastRow());
  let result = [];
  console.log(JSON.stringify(sourceValues)) //log: [[13000],[468],[""],[3900],[3250],[3250],[520],[2600],[910],[1300],[52],[0.023],[6500]]
  let value;
  for (let i = 0; i < sourceValues.length; i++){
    value = sourceValues[i][0]
    if (value === "" || value === 0) {
      result.push([""])
    }else{
      result.push([value * (1 - ratio[i])])}
    }
  console.log(JSON.stringify(result)) //log: [[33800],[468],[""],[1170.0000000000002],[2437.5],[2762.5],[322.4],[1430.0000000000002],[910],[1300],[52],[0.023],[6500]]
  let numFormat = targetRange.setValues(result);
  const rangeList = result.reduce((ar, [e], i) => {
  if (e > 1) ar.push(`C${i + 1}`);
  return ar;
  }, []);
  sh.getRangeList(rangeList).setNumberFormat("#");
  ss.setSpreadsheetLocale("fr_CA");
  
}

result on the google sheet

Expected result

Answer 1

• You want to achieve the number format like 1654.123 -> 1654, 23.456 -> 23, 0.43 -> 0,43, 0.02 -> 0,02, 0.037 -> 0,037 in the cells on Google Spreadsheet.
  • You want to use the values as the number.
• You want to achieve this using Google Apps Script.

Modification points:

• In your scrit, numFormat is the range object. Under this situation, when for (i = 0; i < numFormat.length; i++){ is used, the for loop is not correctly run (the script in the for loop is not run.), because numFormat.length is undefined.
• When you want to change the decimal operator from . to ,, in this case, how about changing the locale of Spreadsheet?
  • At pnuts's answer, Canada (French) is proposed as the locale. Ref

Modified script:

When your script is modified, it becomes as follows.

From:

const sh = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();

To:

const ss = SpreadsheetApp.getActiveSpreadsheet();
const sh = ss.getActiveSheet();

And

From:

for (i = 0; i < numFormat.length; i++){
  switch (numFormat[i] > 0) {
    case numFormat < 0.1:
      numFormat[i].setNumberFormat('#,##0.00')
      ;
    case numFormat < 1:
      numFormat[i].setNumberFormat('#,#0.0')
      ;
    default: numFormat[i].setNumberFormat('#0');
    }
} 

To:

const rangeList = result.reduce((ar, [e], i) => {
  if (e > 1) ar.push(`C${i + 1}`);
  return ar;
}, []);
sh.getRangeList(rangeList).setNumberFormat("#");
ss.setSpreadsheetLocale("fr_CA");

• From your script, it supposes that the number format of the column "C" is modified.

References:

• getRangeList()
• setSpreadsheetLocale()

Added 1:

Although I'm not sure whether this is your current issue, in your script, when the cells are empty in the column "A", the column "C" might not be the empty. If you want to resolve this issue, how about modifying as follows?

From:

result.push([sourceValues[i] * (1 - ratio[i])])

To:

result.push([sourceValues[i][0] ? sourceValues[i][0] * (1 - ratio[i][0]) : ""]);

• In your script, sourceValues and ratio are 2 dimensional arrays.

Added 2:

Unfortunately, I cannot replicate your situation. For example, when your script and values are used like below script, the following result is retrieved.

33800
468

1170
2438
2763
322
1430
910
1300
52
0,023
6500

Sample script:

const result = [[33800],[468],[""],[1170.0000000000002],[2437.5],[2762.5],[322.4],[1430.0000000000002],[910],[1300],[52],[0.023],[6500]];

const ss = SpreadsheetApp.getActiveSpreadsheet();
const sh = ss.getActiveSheet();
const targetRange = sh.getRange(1, 3, sh.getLastRow());
let numFormat = targetRange.setValues(result);
const rangeList = result.reduce((ar, [e], i) => {
  if (e > 1) ar.push(`C${i + 1}`);
  return ar;
}, []);
sh.getRangeList(rangeList).setNumberFormat("#");
ss.setSpreadsheetLocale("fr_CA");