countOccurrences method

int countOccurrences(
  1. String substring
)

Counts occurrences of a substring within the string

Example:

"banana".countOccurrences("a"); // Returns 3
"hello world".countOccurrences("o"); // Returns 2

Implementation

int countOccurrences(String substring) {
  if (isEmpty || substring.isEmpty) return 0;

  int count = 0;
  int startIndex = 0;
  while (true) {
    startIndex = indexOf(substring, startIndex);
    if (startIndex == -1) break;
    count++;
    startIndex += substring.length;
  }
  return count;
}