C + + header file on the issue Two days ago I read a definition of the order of postings on the first document, but can not find one, and I like it, the first definition of this document #include "Iostream> Using namespace std; The first paper on the definition of the order to decide whether the success of the translation process, a day when we wrote the teacher in the class procedures 114,800 illnesses, the head of the order paper for a statement about the results through translation, in the end this is to ask, what principle? I understand the above document is not the first good, experts advise For example, ah bh first paper in the front, Ah included in a defined type variable b bh. When you translated at the main function will be incorrect report, because it Compiler Where no definition of the type b variables. It will not be able to find the translation. A simple example : A.h [code] #ifndef _A_H_ # _A_H_ Struct a{ Struct bb; } #endif [/code] B.h [code] #ifndef _B_H_ # _B_H_ Struct b{ Int c; Long l; } #endif [/code] Main.c [code] #inclue "Ah" #include "Bh" Int Main () { Struct aa; Return 0 } [/code] The translation will be incorrect report. After the order if the documents for a period, no problem. In fact, the solution is to add the previous document ah #include "Bh" The order of succession so that they would not have to rely on a relationship. I know you said this, I would like to ask if this remark, #include<iostream> Using namespace std; #include<stdio.h> Type in the category. H header files, most of which were #include<iostream> Using namespace std; Ahead or behind, this seems to have provided the --> No requirements. White is so much to say. : ( If the yes. H Would not invoke the name space House hufenghuanyu reply to the message Generally using C + + namespace Std first on the final document, but is best not to use too many things because of exposure to the process, what would write what became the --> Not saying that we should not using namespace Std the vs2005, cin, cout not rigidly? [ Closed window ]