Pyramid star pattern in Dart

import 'dart:io';
void main() {
  int rows = 5;
  for (int i = 0; i < rows; i++) {
    for (int j = (rows - i); j > 1; j--) {
      stdout.write(" ");
    }
    for (int j = 0; j <= i; j++) {
      stdout.write("* ");
    }
    stdout.writeln();
  }
}

OUTPUT

    * 
   * * 
  * * * 
 * * * * 
* * * * *