Daniel_C_C的博客

Java Language SpecificationChapter 14.11The type of theExpressionmust bechar,byte,short,int,Character,Byte,Short,Integer,String, or an enum type (§8.9), or a compile-time error occurs.表达式的类型必须是char，byte，short，int或者其包装类型，String，枚举类型，也可以是一...