global

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Why are global and static variables initialized to their default values? See the code, #include <stdio.h> int a; int main(void) { int i; printf("%d %d\n", a, i); } Output 0 8683508 Here 'a' is initialized with '0', but 'i' is initialized with a 'junk value'. Why? 回答1: Because that's the way it is, according to the C Standard . The reason for that is efficiency: static variables are initialized at compile-time ,

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Why are global and static variables initialized to their default values? See the code, #include <stdio.h> int a; int main(void) { int i; printf("%d %d\n", a, i); } Output 0 8683508 Here 'a' is initialized with '0', but 'i' is initialized with a 'junk value'. Why? 回答1: Because that's the way it is, according to the C Standard . The reason for that is efficiency: static variables are initialized at compile-time ,

问题 I have the next problem: when I try to start my camera, I can take the picture, even save it on my sdcard, but when I'm going to get the path for showing it on my device I get errors. My global variables are 2 (I used 1 but 2 are better for making sure it's a strange error): private File photofile; private Uri mMakePhotoUri; and this is my start-camera function: @SuppressLint("SimpleDateFormat") public void farefoto(int num){ // For naming the picture SimpleDateFormat sdf = new

问题 I'm trying to get a sense of best practices in python. If I define a function to access (but not change) a global variable, it's not generally necessary to specify the variable as global in the function. But is it faster to pass the global variable to the function? I ask because I've come across some references to the cost of looking up global variables, but I'm not sure that I understand. For example: def f1(localList): for element in localList: if element in globalSet: pass #do stuff. def

问题 I am using some global variables on a web application, built on Html/Javascript. I am using these variables across pages (or portions of them), and sometimes they are used as post data for ajax calls. My question is: how secure is this? surely i can set different values for these variables (using a console for example) and then, the calls that rely on this var are made. Imagine the user sets some Id that corresponds to something that he even doesn't have access to.. How should this be done?

问题 If I use a function to read the contents of a file in one module: def get_objectstore(): with open(os.getcwd() + "\\data.store", "rb") as infile: objA = cPickle.load(infile) objectstore = eval((str(objA)).translate(string.maketrans(coder, alpha))) return objectstore and I call this function from my main program like this: from main_vars import get_objectstore objectstore=get_objectstore() now objectstore has all images and sound used by my program. How can I use objectstore in all other

问题 In general, I have the following scenario: Fetch product and its related data from database Convert fetched data to php 'product' object cache product object in session The cache is readonly, i.e customers viewing products on the site. But there are calls like getProductIdsByCategory($categoryId) and the productIds from these results are cached too, per user, not using the global cache that I've read about. A problem is that if someone on the admin side adds a new product and relates it to a

问题 I came across this snippet of code: section .text global main ;must be declared for linker (gcc) and then there is a function called main after this line: main: ;tell linker entry point but i don't seem to understand what global main means, and the comment doesn't seem to help much... i am using this site as a reference to Assembly language programming. i can analyse that main refers to the function main, but i don't understand the use of the global keyword... thank you in advance... 回答1:

问题 I'm trying to use $.post within a function, get the results, then return the function true or false based on the results of the $.post callback. However, the callback seems to occur, AFTER the return event of the parent function. Here's the current code the ret variable is always undefined but if I alert() it within the $.post callback, it returns the correct result; function elementExists(key, type, path, appid, pid){ var ret; $.post('?do=elExists', {key: key, type: type, path: path, appid:

问题 I'm trying to use the new(ish) AS3 global error handling class. I am trying to use it within a Flex mxml application. I can't get it to work at all. Below is an entire program that shows the problem. I set this to use Flash Player 10.2 and compiled with the Flex 4.5 SDK. I've tried using Flex SDK 4.0 and 4.5 but I get the error in either case. I must be missing something obvious here. This is a normal Flex SWF file that will be shown on a web page. Assuming I could import the