global-variables

问题 Can someone explain me why this doesn't work: $(function() { var damg = $(".hidden").val(); $("button").click(function() { alert(damg); }); }); jsFiddle: http://jsfiddle.net/raFnT/ Is it good to use global variables? I've also read that it is a slower option than typing it every time? To explain in detail: I have this: $("button").click(function() { alert(damg); }); and the damg is a value of the input: var damg = $(".hidden").val(); When you type something in the input and THEN press the

问题 I defined some global variables in my app by extending Application, as shown below. When I leave the app, open more apps and play a bit with them, and go back to my app, the global variables have been deleted and my app crashes. I've got 2 questions: 1- How can this be possible? 2- How can I force my app to exit when going to background? I know I'm not supposed to do it, but I can't find other solution... Thanks public class GlobalVars extends Application { public static HashMap<Integer,

问题 I know how to pass a variable from one activity to another using global variables. e.g. In one.java: GlobalVars.setColour(0); In two.java: if (GlobalVars.getColour() == 0) ... GlobalVariables.java: private static int colour2; public static int getColour() { return colour2; } public static void setColour(int colour) { colour2 = colour; } What if i have an array in one.java and i need it in another class? ArrayList<String> myArr = new ArrayList<String>(); myArr is uploaded with contacts from

问题 After my previous question, I come up to the following working code that is intended to refresh the DOM periodically by replacing the <div id="test_css_id">...</div> itself. The behavior of both AJAX requests present in the below code is to reload the same code itself. <div id="test_css_id"> <a id="link_css_id" href="test_url.html">LINK</a> <script type="text/javascript"> var refreshTimer; $('#link_css_id').click(function(event) { event.preventDefault(); $.ajax({ url: $(this).attr('href'),

问题 I'm trying to store all my textures in an array. but the images aren't getting returned it would seem here's my code I was under the assumption that my loadTex and loadSpri functions would return and store their data in the array that i made, but it doesn't seem to be working that way because when i run the game they don't show up, just white space. My code probably looks bad, but i'm quite the beginner still and trying to get the hang of things Here's render.cpp #include "render.h"

问题 Consider this small Lua test script. g1 = "Global 1" g2 = "Global 2" function test () local l1 print(g1,g2,l1) end test() Assume you pause the execution at print(g1,g2,l1) and from C++ get all the global variables with this C code: lua_pushglobaltable(L); lua_pushnil(L); while (lua_next(L,-2) != 0) { const char* name = lua_tostring(L,-2); // How do I tell a user defined // global variable (now in name) // from all other environment variables? lua_pop(L,1); } lua_pop(L,1); // global table When

问题 What is the conventional way to set a variable once to be used by all examples in an RSpec suite? I currently set a global variable in spec_helper that checks whether the specs are being run in a "debug mode" $debug = ENV.key?('DEBUG') && (ENV['DEBUG'].casecmp('false') != 0) && (ENV['DEBUG'].casecmp('no') != 0) How do I make this information available to all the examples in the suite without using a global variable and without re-computing the value for each context and/or example? (My

问题 Whenever I submit a plugin to Firefox I get an email telling me some of my variables are leaking into the global scope... once they tell me I fix the issue. But till then is there any way (program?) to check if the variables are leaking into the global scope? Thanks! 回答1: Both JSLint and JSHint will give you warnings when you miss a var . Both are available on Github (JSLint, JSHint) and both can be run from the command line using Node.js, Rhino or any other non-browser environment of your

问题 What does it mean to declare a variable as global and then re-declare it as local like this: int a = 0; int main() { int a = 7; return 0; } I saw this example in a reference, but I don't understand it. please put into consideration that I'm a beginner at programming with C++ 回答1: This means that in your main method if you use only a , you will refer to that one which is declared in that method, because it shadows the global one . To access the global one within main , you need to access via :

问题 When I try to compile the following with g++: const int zero; int main() { return 0; } I get an error about an uninitialized const 'zero' . I thought that global variables were default initialized to 0 [1] ? Why isn't this the case here? VS compiles this fine. [1] For example, see https://stackoverflow.com/a/10927293/331785 回答1: My gcc is slightly more verbose: $ g++ zeroconst.c zeroconst.c:1:11: error: uninitialized const ‘zero’ [-fpermissive] We see that -fpermissive option will allow this