getColumnLabel static method
Converts index
into A1 notation letter label
1 -> A
2 -> B
27 -> AA
Implementation
static String getColumnLabel(int index) {
final res = <String>[];
var block = index - 1;
while (block >= 0) {
res.insert(0, String.fromCharCode((block % 26) + _charCodeUnitA));
block = block ~/ 26 - 1;
}
return res.join();
}