question: public int indexOf ( int ch ) { return indexOf ( ch , 0 ) ; }
target:  Returns the index within this string of the first occurrence of the specified character. If a character with value ch occurs in the character sequence represented by this String object, then the index of the first such occurrence is returned -- that is, the smallest value such that: this.charAt( ) == ch is true. If no such character occurs in this string, then -1 is returned.