global-variables

问题 I'm having a bit of trouble understanding why some variables are local and some are global. E.g. when I try this: from random import randint score = 0 choice_index_map = {"a": 0, "b": 1, "c": 2, "d": 3} questions = [ "What is the answer for this sample question?", "Answers where 1 is a, 2 is b, etc.", "Another sample question; answer is d." ] choices = [ ["a) choice 1", "b) choice 2", "c) choice 3", "d) choice 4"], ["a) choice 1", "b) choice 2", "c) choice 3", "d) choice 4"], ["a) choice 1",

问题 OK, this must have been asked before but I looked like mad and found nothing: I have a simple array in my iphone app which I define like so: @property (nonatomic, strong) NSArray *pages; @synthesize pages = _pages; I've seen this in Apples sample code and thought this is a nice short-cut for writing self.pages (i.e. _pages replaces self.pages) like so: _pages = [[NSArray alloc] init]; but then Apple has this again (not exactly like this, but it appears as if they keep swapping randomly): self

问题 Following are my files and output. All I want to do is get Value of x after func1() as 20 . I have already referred to this answer. I want to know why this do not work? Is it necessary to use import globalVar instead of from globalVar import * globalVar.py #globalVar.py x=10 fun1.py from globalVar import * def func1(): global x x=20 print("X in fun1",x) main.py from fun1 import * from globalVar import * print("X before fun1=",x) func1() print("X after fun1=",x) Output: X before fun1= 10 X in

问题 how can i require a module globally so i can use it in different modules without having to require it again? or do i just have to do that everytime? is there any best practice for this? heres an example of what i am talking about. lets say i have an index.js like this: var a = require('a.js'), utils = require('utils.js'); var str = 'hello this is a test'; str = a.change(str); utils.return(str); a.js var utils = require('utils.js'); exports.change = function(str) { str = str.replace('test',

问题 how can i require a module globally so i can use it in different modules without having to require it again? or do i just have to do that everytime? is there any best practice for this? heres an example of what i am talking about. lets say i have an index.js like this: var a = require('a.js'), utils = require('utils.js'); var str = 'hello this is a test'; str = a.change(str); utils.return(str); a.js var utils = require('utils.js'); exports.change = function(str) { str = str.replace('test',

问题 I want watch for the creation of new global variables in Javascript so that, anytime a global variable is created, an event is fired. I've heard of the watch() function but that is only for watching for specific variable names. I want a catchall. 回答1: I don't know how to make this work "on demand" as soon as a var is created, but I can suggest a polling approach. In a browser window, all global become a member of the global "window" object. (Because technically, "window" is the "global object

问题 1) If I'm not mistaken, C++ standard guarantees that static variables in a single translation unit are initialized in their definition order. And I'm confused about the following code fragment: extern int n; int k = n; int n = 2; extern int n; is the declaration, not the definition, so k is defined before n , but GCC, Clang and MSVC all show me that k == 2 after the initialization of the global variables. For me it's unclear how can k be assigned 2 after int k = n; , because n is not

问题 I have a basic express server that needs to store some global variables during each request handling. More in depth, request handling involves many operation that need to be stored in a variable such as global.transaction[] Of course if I use the global scope, every connection will share information of its transaction and I need a global scope because I need to access the transaction array from many other modules, during my execution. Any suggestion on this problem? I feel like is something

问题 I've been searching all over the net, including stack overflow, how to declare global variables in JS React. I have a declared variable called name and I'd like to use this variable in two different sections of my code. But I it returns as an undefined variable in some sections of the code, even though I've left it outside all the functions, as global variables usually are. Is there supposed to be a special way to declare global variables in React? My Js React Code -- its a very simple sample

问题 In android,Google recommends us to save the global variables in Application. But there is a problem, if the android os kill the application because of low of memory, the application will be re-oncreate and the global variables I saved will be lost. I don't know when to save/restore these variables,application doesn't give us some methods such as onsaveinstancestate()/onrestoreinstancestate(). I have one idea but I can't make sure it can work well. I see some app will go to slashScreen when os