countOccurrences method

int countOccurrences(
  1. String substring
)

Counts the number of non-overlapping occurrences of substring.

'banana'.countOccurrences('an') // 2

Implementation

int countOccurrences(String substring) {
  if (isEmpty || substring.isEmpty) return 0;
  var count = 0;
  var index = 0;
  while (true) {
    index = indexOf(substring, index);
    if (index == -1) break;
    count++;
    index += substring.length;
  }
  return count;
}