//1. false System.out.println(Integer.parseInt("01")>10); //2. abcdefghijklmnopqrstuvwxyz System.out.println("ABCDEFGHIJKLMNOPQRSTUVWXYZ".toLowerCase(Locale.ENGLISH)); //3. true String regex = "CCNB-APPROVAL-[0-9]{8}-[0-9]{1,5}\.ok"; String name = "CCNB-APPROVAL-20150306-01.ok"; System.out.println(name.matches(regex)); //4. false System.out.println(!true); //5. a System.out.println("abc".substring(0,1)); //6. null System.out.println("null"); //编译不通过 System.out.println(null);