definition

问题 I have seen it first time ... in a method signature. I tried to access a .class file. It has a method defined as below public void addGraphData(GraphData... _graphData) { } And that GraphData is nothing but POJO with getters and setters. Why is the .class file displaying GraphData... _graphData instead of GraphData _graphData ?? 回答1: It's varargs and can only be used last in a parameter list. The last param can hold more than one object. public class C { int i; String[] s; public C(int i,

问题 head.h #pragma once namespace foo { int bar; int funct1(); } head.cpp #include "head.h" int foo::funct1() { return bar; } main.cpp #include <iostream> #include "head.h" int main() { foo::bar = 1; std::cout << foo::funct1() << std::endl; return 0; } Error LNK2005 "int foo::bar" (?bar@foo@@3HA) already defined in head.obj I don't understand what is going on. I tried looking for the answer but everyone's questions are so specific to their code and don't even look close to the problem that I am

问题 In order to do runtime transformations in Babel you need to require and use babel-core/register . I have no idea what register means in this sense, i.e. the actual definition. The page isn't very helpful. What does this actually mean? 回答1: ok, so the purpose of babel as you know is to transpile your js current code to an understandable version of js for the given environment, tool, framework you're using. Those vary as listed here, How to use Babel with your tool of choice. In the node

问题 Where is struct proc_dir_entry defined in linux kernel? in /linux/proc_fs.h it is just declared as: (kernel 3.10) struct proc_dir_entry; and I think because of this I get this error: dereferencing pointer to incomplete type at this line of code though including /linux/proc_fs.h : while(strcmp (my_dir_entry->name,"tcp")) 回答1: It is defined in fs/proc/internal.h . 来源： https://stackoverflow.com/questions/19334023/struct-proc-dir-entry-definition-in-kernel

问题 I've finally remembered what to ask. I never really got what : and ? do when a variable is being defined like this: $ip = ($_SERVER['HTTP_X_FORWARDED_FOR']) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR']; As you can see there is ? and : and ( ) Could anyone give me a brief detail about why and how they are used for? 回答1: The expression looks like this: $var = (condition) ? if_true : if_false ?: is the ternary operator . If condition is true, $var will be assigned the value if

问题 int x; Is this a declaration or a definition? As I write the following code, #include <stdio.h> int main(void) { int x; printf("%p",&x); return 0; } it prints some address. So as memory is allocated, int x; can't be just a declaration. So is it a definition? 回答1: From the C standard (n1256): 6.7 Declarations ... 5 A declaration specifies the interpretation and attributes of a set of identifiers. A definition of an identifier is a declaration for that identifier that: — for an object, causes

问题 what is a baseline and what is a benchmark? what is the best definition for these and how do you baseline a set of numbers and benchmark another set? 回答1: HI Gagneet, I'm on the Windows performance team: here is how we use these terms. A baseline is a measurement of a known configuration that is used as a reference for subsequent measurements. For base line, we characterize the thing being measured: lets take cold boot time for example. Here we have a set of machines that are well

问题 What exactly is NoSQL? Is it database systems that only work with {key:value} pairs? As far as I know MemCache is one of such database systems, am I right? What other popular NoSQL databases are there and where exactly are they useful? Thanks, Boda Cydo. 回答1: From wikipedia: NoSQL is an umbrella term for a loosely defined class of non-relational data stores that break with a long history of relational databases and ACID guarantees. Data stores that fall under this term may not require fixed

问题 I'm learning Objective-C, and have a C/C++ background. In object-oriented C++, you always need to declare your method before you define (implement) it, even if it is declared in the parent class. In procedural-style C, IIRC, you can get away with just defining a function so long as it is only called from something else in the same compilational unit (ie. the same file) that came later on in the file (well, provided you don't declare it elsewhere with "extern"). Now, in Objective-C, it appears

问题 What's the definition of a Shim? 回答1: From Wikipedia: In computer programming, a shim is a small library that transparently intercepts an API, changing the parameters passed, handling the operation itself, or redirecting the operation elsewhere. Shims typically come about when the behaviour of an API changes, thereby causing compatibility issues for older applications that still rely on the older functionality. In these cases, the older API can still be supported by a thin compatibility layer