addPatternAt method

String addPatternAt(
  1. int index,
  2. String pattern
)

Implementation

String addPatternAt(int index, String pattern) {
  if (index < 0 || index > length) {
    throw RangeError('Invalid index: $index. String length: $length');
  }
  return substring(0, index) + pattern + substring(index);
}