countOccurrences function
Count non-overlapping occurrences of pattern in text.
Implementation
int countOccurrences(String text, String pattern) {
if (pattern.isEmpty) return 0;
var count = 0;
var start = 0;
while (true) {
final idx = text.indexOf(pattern, start);
if (idx == -1) break;
count++;
start = idx + pattern.length;
}
return count;
}