global

google app engine persistent globals

由 故事扮演 提交于 2019-12-08 04:00:19
问题 I'm looking for a way to keep the equivalent of persistent global variables in app engine (python). What I'm doing is creating a global kind that I initialize once (i.e. when I reset all my database objects when I'm testing). I have things in there like global counters, or the next id to assign certain kinds I create. Is this a decent way to do this sort of thing or is there generally another approach that is used? 回答1: The datastore is the only place you can have guaranteed -persistent data

how to pass text between views

由 喜夏-厌秋 提交于 2019-12-08 03:39:50
问题 i made 2 views and i want to send text of label on main view to sub view to an want to print it there on another label's text value.... how to pass that text 回答1: I wouldn't use a singleton pattern or any other 'global variable'. This will make your view controllers very tightly coupled and restricts reusability. I would just create a instance variable in the second view controller and set this in the main one before presenting the view. The second view controller then sets the label.text to

Hibernate Sequence Id Specification

由 我怕爱的太早我们不能终老 提交于 2019-12-08 03:10:23
问题 I have this annotation to specify a sequence id: @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "parametro_seq_gen") @SequenceGenerator(name = "parametro_seq_gen", sequenceName = "PARAMETROS_SQ", allocationSize = 1, initialValue = 1) I find it very verbose to repeat on all my entities. Is there any way to create a custom annotation or something ? I want to specify only the sequence name . 回答1: That's easy! Just create a package-info.java where entities are stored and

Global Pointer in C?

由 ≯℡__Kan透↙ 提交于 2019-12-08 02:38:24
I know a pointer is usually assigned upon its declaration, but I wondering if there's any way to create a global pointer in C. For example my code below: is it a good practice? static int *number_args = NULL; void pro_init(int number) { number_args = &number; /* initialize the pointer value -- is this okay? */ } Avoid globals - They are a bad idea and usually lead into problems. You are taking an address of a variable on the stack. That will get reused somewhere down the line and hence having unintended results. If you feel the need (why?) to have a global pointer then initialise if off the

How to declare a variable for global use

由 浪子不回头ぞ 提交于 2019-12-08 01:14:16
问题 I've searched forum for similar issues and as I understand, global variables is to be avoided. For me that is not logical yet, as I'm new to programming. If I've understood all this correctly, a static variable should do the job that I'm looking for. I've made a combobox of four choices in the mainwindow and when a comboboxitem is selected, variable b is declared. This is done in a private void SelectionChanged. When the comboboxitem declaring variable b is selected, a usercontrol pops up. I

Python新手学习基础之函数-全局变量和局部变量

由 一笑奈何 提交于 2019-12-07 19:26:50
全局变量和局部变量 我们通常把定义在函数外的变量成为全局变量，定义在函数内的变量称为局部变量，顾名思义，全局变量的作用域是整个代码段，局部变量的作用域就只是在它所属的代码段，变量只在它的作用域里有效。 通过实例，我们可以进一步理解下，全局和局部的概念。 count = 10 #全局变量 def print_local(): count = 5 #局部变量，这个count覆盖了全局变量count，这2个是不同的变量。 print(count) def print_global(): print(count) #这里的count是最上面的全局变量噢 print_local() print_global() 结果会是？ global语句 从上面课的代码中可以发现，如果在函数体内声明的变量名和已经有的全局变量名重复，那么局部变量就会把全局变量覆盖掉。如果想要在函数体内使用全局变量，使用前需要先用global语句来声明下用到的这个变量是全局变量。 count = 10 #全局变量 def print_local(): global count #声明count是全局的 count = 5 #这个count就是上面的全局变量 print(count) def print_global(): print(count) print_local() print_global() 更多学习内容

I need to make a global array in C with a size inputted by the user

由 痴心易碎 提交于 2019-12-07 17:40:40
问题 Basically I need to make a global variable in C that is an array. The Array will be [n][22][n+1] where n is either 3,4,5 or 6 and is selected by the user. Is there a way to do this or should I just make the array [6][22][7], and have the functions dealing with it only use the parts up to n (if that makes any sense)? I've had to do this before for a computer science class but can't remember exactly how to do it. 回答1: For an array that small (well, assuming reasonably sized data types), you

Why am I able to global a non-existing variable in python

由 我怕爱的太早我们不能终老 提交于 2019-12-07 17:29:41
问题 First, I fully understand what global statement means and how to use. Now, let's look at this: x = 100 def f(): global x global xxx x = 99 return x print(f()) # >>> 99 print(x) # >>> 99 You can see that by using global x , I successfully changed the value of x in the global environment. But xxx does not exist at all, why am I allowed to global it and it won't even bring any error even if the function is executed? 回答1: global x does not define, declare, or otherwise create x . It simply states

C++: Global variable as pointer

由 醉酒当歌 提交于 2019-12-07 16:48:49
问题 I am new to c++ and have one question to global variables. I see in many examples that global variables are pointers with addresses of the heap. So the pointers are in the memory for global/static variables and the data behind the addresses is on the heap, right? Instead of this you can declare global (no-pointer) variables that are stored the data. So the data is stored in the memory for global/static variables and not on the heap. Has this solution any disadvantages over the first solution

Javascript Global Variables

由 久未见 提交于 2019-12-07 13:31:00
问题 How should I create a changing variable as a global variable? so something like: function globVar(variable){ window.variable; } So in this way I could create global variables in an automatic mode too, and also I could create them for myself easier :) EDIT For example I could create a global variable just like this: globVar('myVariable'); then myVariable is added to the global variables. 回答1: Sorry to say this, but the answers you have received are bad habits that you should stay away from. A
订阅 global