global-variables

问题 I am trying to access a result in a dictionary held in a Python global variable within JavaScript. var selected = jQuery('.target option:selected').text() var list = "${c.persons_by_permission["+selected+"]}" If I directly access the dictionary without the using the variable: var list = "${c.persons_by_permission['stringID']}" Then the code works. However, when I am trying to use the variable to access the dictionary I get a syntax error (I believe its because of the curly braces). I have

问题 I have a function that uses lots of global vars and arrays - e.g. $a=1; $b[0]='a'; $b[1]='b'; $c='Hello'; function foo() { echo "$a $b[0] $b[1] $c"; } I understand that as opposed to JS, you have to include the vars when you call the function: function foo($a,$b,$c) but since I'm using lots of different vars and arrays in the function, and since the main origin of most of the vars is the $_GET array (after using extract($_GET)), I'm not sure how to do this. is there a way to make a PHP

问题 I have a VB application, that uses some global variables to store data that is required by multiple forms and modules, this works fine. However if a user opens up another workbook, running the same VBA application, then they end up accessing (and changing) the same public variables. How can I have workbook level global variables, or if this is not possible, what is the best way to store data that is accessible by all forms and modules, but only inside the specific workbook? This is a VBA

问题 var id = $(this).children().html(); // id is 5 $.ajax({ url: 'ajax.php?id=' + id, success: function(data) { id = data; // id is 1 } }); if(id == 1){ // id is again 5 ... } Why in the following example I can't reinitialize the id variable? What is wrong? Thanks. 回答1: The $.ajax() function has to go and get the data, it hasn't done this and executed your success callback by the time it reached the code immediately after. Your code order actually happens like this: var id = $(this).children()

问题 var id = $(this).children().html(); // id is 5 $.ajax({ url: 'ajax.php?id=' + id, success: function(data) { id = data; // id is 1 } }); if(id == 1){ // id is again 5 ... } Why in the following example I can't reinitialize the id variable? What is wrong? Thanks. 回答1: The $.ajax() function has to go and get the data, it hasn't done this and executed your success callback by the time it reached the code immediately after. Your code order actually happens like this: var id = $(this).children()

问题 I have a C file which contain a global variable foo. How I can access foo from another assemby program. I am using i586-elf-as (GNU assembler) and i586-elf-gcc (gnu compiler) for building. 回答1: You can just use the symbol name; as treats all undefined symbols as external. Check compiler output ( gcc -S ) and/or documentation to find out if C variable names get a leading _ prepended or not. ( int myglobal becomes asm _myglobal on many non-ELF platforms, but still myglobal on Linux/ELF.) And of

问题 I wonder if there is any difference in performance when accessing a class variable (a dict) inside a method of the same class using: self.class_variable_dict.add(some_key, some_value) and ClassName.class_variable_dict.add(some_key, some_value) obviously, both will work as long as there is no instance variable with the same name, but is there any reason/use case for which we should prefer one over the other? 回答1: Accessing it via ClassName rather than via self will be slightly faster, since if

问题 foo = "foobar"; var bar = function(){ var foo = foo || ""; return foo; } bar();` This code gives a result empty string. Why cannot JS reassign a local variable with same name as a global variable? In other programming languages the expected result is of course "foobar", why does JS behave like that? 回答1: That's because you declared a local variable with the same name - and it masks the global variable. So when you write foo you refer to the local variable. That's true even if you write it

问题 I have been researching this problem for a long time, and I can't seem to find the answer to this question. I am fairly new to iPhone programming, so sorry if this is a stupid question. If anyone has just specific code to post showing how this can be done, that will be very helpful. 回答1: Objective-C is a superset of C, so just do it the C way: int globalX = 100; And header file: extern int globalX; 回答2: You do it exactly the way you would in C. Here's a simple example: int myGlobal = 3; 回答3:

问题 Does PHP have global variables that can be modified by one running script and read by another? 回答1: No, by design PHP is a "share nothing" architecture, which means nothing is shared between processes running at the same time or between requests running one after another. There are ways to share data, but you have to do it explicitly. If you just want to share between 2 requests from the same user, sessions or cookies might be the way to go. If you want to share between multiple users, you