c# get all occurrences of a string
public List<Integer> findWordUpgrade(String textString, String word) {
List<Integer> indexes = new ArrayList<Integer>();
StringBuilder output = new StringBuilder();
String lowerCaseTextString = textString.toLowerCase();
String lowerCaseWord = word.toLowerCase();
int wordLength = 0;
int index = 0;
while(index != -1){
index = lowerCaseTextString.indexOf(lowerCaseWord, index + wordLength); // Slight improvement
if (index != -1) {
indexes.add(index);
}
wordLength = word.length();
}
return indexes;
}