javascript - Google Scripts / Sheets Add prefix to data once it has been entered into the cell

Question

Objectives

1. Add a Prefix of CSC1[Leading Zeros] to a number such as 1291 or 12922 or 129223 this should apply to the whole column (Column F)
2. Ensure total string length is = 15 using padding of zeros so the cell value would be CSC100000001291
3. The user would only enter 1291 but I plan to make the script overwrite this to make the the cell value CSC100000001291

Can be done using a formula but across two columns but would prefer to use one column as it look tidier.

e.g [User Input] = [Final Cell Value]

 - 1291 = CSC100000001291
 - 12922 = CSC100000012922

Currently trying to work this one out

Answer 1

Use the following:

• An onEdit trigger to check when someone has updated a cell
• padStart() to add the leading zeros
• replace() the first 4 zeros with "CSC1" (since only the first occurrence will be replaced if passing a string instead of regular expression)
• setValue() to update the edited cell

function onEdit(e) {
  if (e.range.columnStart == 1) { // Column A
    const padded = e.value.padStart(15, 0);
    e.range.setValue(padded.replace('0000', 'CSC1'));
  }
}