google sheets script loop over rows code example

Example 1: read every cell in a column google app script

function appendString() {
  var range = SpreadsheetApp.getActiveSheet().getActiveRange();
  var values = range.getValues();

  var modified = values.map(function (row) {
    return row.map(function (col) { 
      return col + " string"; 
    }); 
  })

  range.setValues(modified);
}

Example 2: read every cell in a column google app script

function appendString() {
  const range = SpreadsheetApp.getActiveSheet().getActiveRange();
  const values = range.getValues();
  const modified = values.map(row => row.map(currentValue => currentValue + " string"));
  range.setValues(modified);
}