global-variables

问题 I am using postgresql 9.4 and while writing functions I want to use self-defined error_codes (int). However I may want to change the exact numeric values later . For instance -1 means USER_NOT_FOUND. -2 means USER_DOES_NOT_HAVE_PERMISSION. I can define these in a table codes_table(code_name::text, code_value::integer) and use them in functions as follows (SELECT codes_table.code_value FROM codes_table WHERE codes_table.code_name = 'USER_NOT_FOUND') Is there another way for this. Maybe global

问题 This question already has answers here : How to print value of global variable and local variable having same name? (4 answers) Closed 2 years ago . for example #include<stdio.h> int foo = 100; int bar() { int foo; /* local foo = global foo, how to implemented? */ return 0; } int main() { int result = bar(); return 0; } I think in the function bar, calling foo directly will just get the global foo. How can I refer the local foo? I know in C++, there is this pointer. However, does C has

问题 What is default storage class of a global variable? While searching on web I found, some sites say it is static . But, static means internal linkage and the variable can not be available outside the file scope i.e it should not be available to other object files. But, they still can be accessed to other files using declarations like extern int i . And, if I explicitly mention static to global variable then it is not available outside the file scope. Then, what is correct default storage class

问题 In my project we have some global variables that work as containers: MyProject.MyFreature.someFunction = function() { ... } So then I use that script across the site and JSLint / JSHint complains about that: 'MyProject' is not defined I know that I can go to every JavaScript file and add the comment /*global MyProject*/ on top of it. But I'm looking a way to define that comment in some sort of config file so I don't have to go file by file adding this comment. Some kind on option in the

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed last year . I generally live by the rule that Global variables / functions are evil and that every piece of code should live in the class to which it pertains. This is a very easy rule to follow, and I believe that I haven't ever run into an issue with this rule until now. Today, however,

问题 I read several posts on C++ initialization from Google, some of which direct me here on StackOverflow. The concepts I picked from those posts are as follows: The order of initialization of C++ is: Zero Initialization ; Static Initialization ; Dynamic Initialization . Static objects (variables included) are first Zero-initialized , and then Static-initialized . I have several inquiries as to the initialization issue ( storage class issue may be related as well): Global objects (defined without

问题 I'm trying to improve my understanding of the global namespace in javascript and I'm curious about a few things: is there a "GOD" (i.e. a parent) object that all objects (since all things except primitives are objects) to answer to and if so would that object be "window" ? why is it bad idea to have vars/functions on a global level? if it is really a bad idea to have vars/functions in global scope then would closures be the best way to avoid this? example: function parent(){ var x = 'some

问题 #include <stdio.h> int i=10; int j=i; int main() { printf("%d",j); } I get an error stating that initialization element is not a constant? What is the reason behind this? 回答1: What is the reason behind this? C(unlike C++) does not allow initialization of global values with non constant values. C99 Standard: Section 6.7.8: All the expressions in an initializer for an object that has static storage duration shall be constant expressions or string literals. 回答2: You could try using: int i=10;

问题 I was wondering if anybody knows the total length that a post global could be. e.g: $_POST['formInput'] = "hello world, how long can i be?"; I am creating a site where someone will enter an unknown amount of chars into a textarea, so potentially it could be 2 pages on a word document. So if anybody knows of any other methods of how i can do this apart from using a post global? (it cant be saved in a file, as its important data that i dont want other people to find) That would be very helpful.

问题 I'm trying to figure out how i can use a variable, that has been set outside a function, inside. Is there any way of doing this? I've tried to set the variable to "global" but it doesn't seems to work out as expected. A simple example of my code $var = '1'; function() { $var + 1; return $var; } i want this, to return the value of 2. 回答1: You'll need to use the global keyword inside your function. http://php.net/manual/en/language.variables.scope.php EDIT (embarrassed I overlooked this, thanks