Google Sheet Script That Reads Cell "a" And Writes To Cell "b" Based Off Cell "a" Value

Good morning all, I need to write a script for Google Sheets that checks if a cell in the row contains a value it will write a value to a column on that row. For example, If cell i

Solution 1:

An Apps Script solution to this request needs to inspect each array index, and write to the corresponding index in the other range. To maximize speed, we want to use the batch operations getValues() and setValues when possible. One possible solution would look like this:

function setNewIssueLabels() {
  const sourceRangeA1 = "C3:C1000", destStart = "G3";

  const sheet = SpreadsheetApp.getActive().getActiveSheet(),
        source = sheet.getRange(sourceRangeA1).getValues();
  if (!source.length || source[0].length !== 1)
    throw new Error("Expected single-column source range with at least 1 row");

  // Include the original row index in the array.
  const inputs = source.map(function (row, index) {
    row.unshift(index);
    return row;
  })
  // Keep rows where the 2nd index (the original content) is not a null string.
  .filter(function (iRow) {
    return iRow[1] !== "";
  });

  var dest = sheet.getRange(destStart);
  if (dest.getNumRows() < source.length)
    dest = dest.offset(0, 0, source.length, 1)
  const outputs = dest.getValues();

  // For every row in 'inputs' (read: every row in the source range that
  // has a value), do stuff.
  inputs.forEach(function (iRow) {
    var originalIndex = iRow[0];
    // var originalContent = iRow[1];
    // var isActualNewIssue = outputs[originalIndex] === "";
    // if (isActualNewIssue) {
    outputs[originalIndex] = "New Issue";
    // } else {
    //   foo();
    // }
  });

  /**
   * Overwrite the contents of the destination range with the 'outputs' values,
   * which will be whatever was previously there, and possibly additional
   * cells with "new Issue"
   */
  dest.setValues(output);
}

I've added and commented out some logic for determining if the value was present on the previous invocation of the function, or if it is genuinely new.

Solution 2:

Turns out a simple formula can do this on it's own without a script.

"=ArrayFormula(if(len(C2:C),"New Issue",))" is all it takes.