reference

问题 sub function{ my $storedata=shift; my $storenameandaddress=$storedata->{$storeid}->{name} ."_".$storedata->{$storeid}->{location}->{address} ."_".$storedata->{$storeid}->{location}->{city} ."_".$storedata->{$storeid}->{location}->{state} ."_".$storedata->{$storeid}->{location}{country};} My codes are shown above. and it gives me error message: Using a hash as a reference is deprecated at main.pl line 141. However, the function is still runable. And all the rests seem fine. So what is this

问题 My question revolves around whether or not I must expose my use of the boost::shared_ptr from my interface and whether or not I should expose raw pointers or references from my interface. Consider the case of a Person who has an Employeer . Employeer internally maintains all of its employees in a vector< shared_ptr< Person > > . Because of this, do best practices dictate that any interface involving Person should be a shared_ptr wrapped person? For example, are all or only some of these ok:

问题 I have a table Called 'usertab' to store user details such as: userid uuid, firstname text, lastname text email text gender int image text Most of the other tables contains userid as a field for referencing 'usertab', but when I retrieve data from other table, I need to execute another select query to get user details. So if 10,000 or more data retrieved, same number of select query executed for getting user details. This makes our system slow. So we add usertab fields such as firstname

问题 I had asked a previous question about references and undefined behavior here: previous question and based on the answer given and some of the comments such as the comment by user2079303 where they stated this: A reference wrapper works fine, if you have one "master" container that contains the objects themselves (not references) that is never modified, and other containers have references to the master My new question becomes this: Will this help alleviate the possibility of dangling

问题 If we want to get a value from a method, we can use either return value, like this: public int GetValue(); or: public void GetValue(out int x); I don't really understand the differences between them, and so, don't know which is better. Can you explain me this? Thank you. 回答1: Return values are almost always the right choice when the method doesn't have anything else to return. (In fact, I can't think of any cases where I'd ever want a void method with an out parameter, if I had the choice. C#

问题 this question is in relation to my previous question: Linq2Entity Getting Values from reference Table Now i have the problem that i want to add a new entry in Table B. I tried something like this: ObjectQuery<A> aTable = dbConnection.A; ObjectQuery<B> bTable = dbConnection.B; var data = from d in aTable //Reference dataset in Table A where d.ID == myID select d; B bData = new B() { ID = GetNewID(), Text = text, A = data.First() }; dbConnection.AddToB(bData); but this "A = d.First()" does now

问题 Hi I have a problem with java and dll. I need to pass string value to dll by reference but, It's not successful. public short ReadData(int block_id, int offset, int data_size,StringByReference dataBuf, IntByReference err_code); The problem is StringByReference dataBuf , I try many way to find solution but it doesn't work. The call function is: ReadData(0, 4, 13, ??? , status); Cause it Had no .dll document. function `public static short Read_Data(int card_type, int block_id, int offset, int

问题 What exactly is wrong with referencing both System.Web and System.Windows.Forms in my class library? For example, library could contain some code which needs to reference Web or WinForms-specific classes. 回答1: Well, if you do this, you will have overhead if you use that library and the danger, that Web code uses the Forms lib and vice versa. I would split it in 3 Parts - a common one and one Web and one Forms part, so you only have to use the common and the part you need. By that, you

问题 If I have a function in php that creates several arrays of objects from parsing xml, how do I return those arrays as references? Do I need to call new to allocate the arrays? How do I define them within the function? function ParseConfig($rawxml, &$configName, &$radioArr, &$flasherArr, &$irdArr) Sorry, I mean return multiple arrays as parameter references. what do I do to create the array inside the function? or can I just start using it as an array? 回答1: I hadn't noticed that you edited your

问题 This question already has answers here : Meaning of '&variable' in arguments/patterns (1 answer) What is the difference between `e1` and `&e2` when used as the for-loop variable? (1 answer) What's the difference between ref and & when assigning a variable from a reference? (3 answers) Closed 9 months ago . I came across below example in Rust book. for &item in list.iter() { if item > largest { largest = item; } } I suppose it means list.iter() returns the reference to the elements in the list