static int indexOf ( String source , String target , int startIndex , boolean ignoreCase ) { if ( ignoreCase ) { return indexOf ( source , target , startIndex , IGNORING_CASE ) ; } return indexOf ( source , target , startIndex , ( c0 , c1 ) -> Integer . compare ( c0 , c1 ) ) ; }
Returns the index of the first appearance of the given target in the given source starting at the given index . Returns - 1 if the target string is not found .