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成员方法在内存中是否只有一个副本? 以前看C++的时候,看到实例的成员变量在内存中是互不相干的,但是成员方法则是所有实例共用的。现在开始看Java了,Java中的实例成员变量和C++的一样,在内存中是每一个实例一个副本。我猜想实例成员方法应该在内存中只保存一个副本,所有同一个类的实例共用这个实例的成员方法。但是一直没有看到什么资料说起这个问题。请教高手指点迷津,如果能够给出参考资料更好。先行谢过
http://algorithmicbotany.org/网站现在如何访问 http://algorithmicbotany.org/网站现在如何访问L-System的经典网站,可是现在不能访问了,请问哪位高人知道现在如何访问。请不吝指教。
孤独的老七 http://tieba.baidu.com/f?kz=354028543里面说高城是孤独的,我赞成,具体内容自己去看吧。好,写得好,什么事情你要是太突出了,或者太想完美了,或者想做太好了,或者太讲原则了……,你这个人就没有朋友了。老七,我和你共鸣。共鸣的还有《白鹿原》里面白嘉轩的姐夫,临死的时候对他老婆喊了一声“妈”,然后是满眼的泪水。
六一语录 锤子起来,你就倒下
史今语录 我就是一个兵
MS SQL中的逻辑读和物理读有什么区别 use indexTuneDemo/*一个实验数据库*/goset showplan_text offgoset statistics io onselect uid, name, content from foxman where uid='m123456781'执行上面查询之后,在查询分析器的下半部的窗口中列出了查询的IO量:显示扫描次数1,逻辑读43次, 物理读0次, 预读0次,请问这里的扫描次数、逻辑读、物理读、预读都是什么意思?望高手赐教,谢谢。
数据库角色各自有何权限 各位高人,鄙人初涉MS SQL Server 2000,打开数据库后,角色中有如下各种:db_accessAdmindb_backUpOperatordb_dataReaderdb_dataWriterdb_ddlAdmindb_denyDataReaderdb_Ownerdb_securityAdminpublictargetServerRole他们各自表示什么意思,有什么特权?他们和数据库系统管理员、数据库操作员等各种角色的关系是怎样的?
请问日志截断模式是什么模式? 我在看书的时候看到truncate.log on chkpt.选项设置为true,当数据库处于日志截断模式时,一个检查点会截断日志中非活动部分。请教一下,日志截断模式是怎样一种模式,另外,日志有几种模式?先行谢过。
C语言中的小类型隐含转换为大类型出错问题。 下面这个程序:main(){int i=10;clrscr();printf("%x,%lx\n",i,i);printf("%d,%ld\n",i,i);}执行时我本来以为会输出不同进制的10,但是结果却是这样的:a,3c8000a,10,63438858。看起来有点类似符号扩展,但是又不是很像。请教高手,C语言中的小类型数据转换为大类型数据时,难道自己还会出错,原因在哪里,谢谢。
MS SQL Server 2000有没有调试功能 请教高手。MS SQL Server2000 中有没有单步执行的功能,类似TC中的单步运行,增加变量观察窗口等功能,怎样使用。谢谢
三个表中的两个分别进行连接,查询都能成功,但是在一起就失败,为 use bookManageselect *from myBook inner join presson myBook.pressName=press.name运行成功use bookManageselect *from myBook inner join myWriteBookon myBook.isbn=myWriteBook.isbn运行成功use bookManageselect *from myBook inner join myWriteBookinner join presson myBook.isbn=myWriteBook.isbnon myBook.pressName=press.name错误如下:服务器: 消息 107,级别 16,状态 3,行 2列前缀 'myBook' 与查询中所用的表名或别名不匹配。请教高手,问题出在哪里?
master等系统自带的数据库不见了怎么办? 用windows系统账户登陆后,发现在企业管理器中的master、tempdb、pubs等数据库不见了,但是在查询分析器中用可以见到,请教高手,如何才能把这些数据库找回来,谢谢。
MS SQL Server 2000中的natural join是不是没有 microsoft Sql Server 2000中是不是没有自然连接,我始终没有查询成功,而natural又是以蓝色显示的,请高手指教
MS SQL Server 2000中的集合查询 请教高手,Microsoft Sql Server 2000中的集合查询是不是只有union查询,而intersect和except查询是不是没有提供?
rfc791下的2.3节的Addressing中的第三段的最后一句不懂 That is, provision must be made for a host to have several physical interfaces to the network with each having several logical internet addresses.详细出处:rfc791下的2.3节的Addressing中的第三段的最后一句,我总是也弄不懂这一句,请高人给指点迷津。现在把整个第三段贴到下面:Care must be taken in mapping internet addresses to local net addresses; a single physical host must be able to act as if it were several distinct hosts to the extent of using several distinct internet addresses. Some hosts will also have several physical interfaces (multi-homing). That is, provision must be made for a host to have several physical interfaces to the network with each having several logical internet addresses.谢谢
如果你认认真真读懂十个RFC,就没有人敢小看你 记得曾经看过一篇帖子,里面说到学习网络,给出了一条建议:如果你认认真真读懂10个RFC,就没有人敢小看你。可是我惊讶地发现,这里这个RFC吧居然这么的领情,呼唤大家共同努力,让RFC吧火起来。
rfc791(IP协议)中的一段怎么也弄不清楚,请教比我强的人 Care must be taken in mapping internet addresses to local net addresses; a single physical host must be able to act as if it were several distinct hosts to the extent of using several distinct internet addresses. Some hosts will also have several physical interfaces (multi-homing). That is, provision must be made for a host to have several physical interfaces to the network with each having several logical internet addresses.在这一段里面的That is, provision must be made for a host to have several physical interfaces to the network with each having several logical internet addresses.搞不太懂,请哪位为我翻译一下,并且划分一下句子的成分——哪些是修饰哪些的,谢谢。
请教《The C Programming Language》中几个怎么也搞不懂在具体环境 下面几个句子是小老头我在看《The C Programming Language》中遇到的,其中的几个短语始终弄不清楚,请知道者指教,先行谢过。1. 句子:There are now signed and unsigned forms of all integer types, and notations for unsigned constants and hexadecimal character constants. 疑问:notations for unsigned constants and hexadecimal charater constans.notation在这里什么意思?character在这里又是什么意思?如何理解这句话。 出处:《The C Programming Language》第2段。2. 句子:String constants may be concatenated at compile time. 疑问:concatenate是连接,但是在这里如何理解这个句子,字符串常量在编译的时候如何连接,和谁连接。 出处:《The C Programming Language》第2段。3. 句子:Enumerations have become part of the language, formalizing a feature of long standing. 疑问:long standing 在这里什么意思。 出处: 《The C Programming Language》第2段。4. 句子: For external names, the standard guarantees uniqueness only for 6 characters and a single case. 疑问:在这里的a single case什么意思,是不是仅仅有这一种情况。 出处:《The C Programming Language》2.1节下面的第2段。5. 句子:for instance, if chars are 8 bits, unsigned char variables have values between 0 and 255, while signed chars have values between -128 and 127 (in a two's complement machine.) 疑问:in a two's complement machine是什么意思。 出处:《The C Programming Language》2.3节向上第4段。6. 句子:Whether plain chars are signed or unsigned is machine-dependent, but printable characters are always positive. 疑问:plain chars什么意思。 出处:《The C Programming Language》2.3节向上第4段。7. 句子:The type long double specifies extended-precision floating point. As with integers, the sizes of floating-point objects are implementation-defined; float, double and long double could represent one, two or three distinct sizes. 疑问:implementation-defined什么意思 出处:《The C Programming Language》2.3节向上第3段。谢谢各位
请教《The C Programming Language》中几个不会翻译的词汇 1.A Special Case.出处:The line nl = nw = nc = 0;sets all three variables to zero. This is not a special case, but a consequence of the fact that an assignment is an expression with the value and assignments associated from right to left. It's as if we had written nl = (nw = (nc = 0));(标题书中的1.5.4节的第三段)2.Magic Number.出处: You'll also find that it's easier to make extensive changes in programs where magic numbers appear only as symbolic constants. (标题书中的1.5.4节的第二段最后一句)
那人,仍然在我心中 明知相思无用处,唯祝好梦皆无数。××,我手好疼啊。生产资料楼西 彤心幼儿园。多年后,我已经结婚,并且有了孩子,也许你也是,但是,还是时常想起你。
sizeof(char)和sizeof(char型常量)结果不一致 本来是想测试一下sizeof("a")和sizeof('a')的区别,程序如下:main(){printf("\n%d,%d",sizeof("a"),sizeof('a'));}输出结果为:2,2于是编写了下面这个小程序:main(){char c='a';printf("\n%d,%d,%d",sizeof(char),sizeof(c),sizeof('a'));}输出结果1,1,2。请指点。
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