public int indexOf(int ch){
  return indexOf(ch,0);
}

public int indexOf ( int ch ) { return indexOf ( ch , 0 ) ; }
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 .
