declaration

问题 I noticed once that when I declare an array, int arr[10]; after a while the value of array member changes although nothing affects it during a period. Then I made use of dynamic allocation with "new" and the problem solved. I thought that everything should be declared dynamically. But this shouldnt be true. What may be a logical reason? 回答1: Could be number of reasons: Initialize your array member if it is on local storage or it contains any random value if you didn't. You probably overwrite

问题 I noticed once that when I declare an array, int arr[10]; after a while the value of array member changes although nothing affects it during a period. Then I made use of dynamic allocation with "new" and the problem solved. I thought that everything should be declared dynamically. But this shouldnt be true. What may be a logical reason? 回答1: Could be number of reasons: Initialize your array member if it is on local storage or it contains any random value if you didn't. You probably overwrite

问题 I am trying to figure out how I can pass a variable as the declaration type (object) for a class in Python 3. Example: #class defintion class TestClass(Document): test = IntField() me = MongoEngine(app) testInstance = TestClass(me.Document) # How do i pass the Document variable I tried passing an instance of the MongoEngine variable as a variable to the TestClass but this isn't working properly? 回答1: I think you need to structure your class slightly different. Don't put Document in the class

问题 Using 32 bit MASM assembly with the MASM version 11 SDK, I discovered an error during compiling. The error pointed to the line where I declared a variable with a double-word (dd) size. The message said the variable was too small for the string I tried to assign to it. When I defined my variable as a byte instead (db) the program was compiled with no error. This implied that declaring a variable with the db instruction could allow more storage than declaring a double-data size. Below is the

问题 I have a JS library that does something like so: let OptionalLib; function foo() { OptionalLib = require('optionallib'); // Do stuff... return (something from optional lib); } then I add typings in a .d.ts file: declare module 'mylib' { import { Bar } from 'optionallib'; export function foo(): Bar; } the problem with this is that if the optional library is not installed, TS will complain about not being able to import it, even though it's optional. I tried doing this in order to have the

问题 Is it possible to share a Hash_table defined in one kernel module in another kernel module. /*Hash table declarartion and definition*/ DEFINE_HASHTABLE(my_hash_table, HASH_TABLE_BITS); I am populating this table in one module, however I would like to access this table in another module as well. Does extern declaration work here. extern DEFINE_HASHTABLE(...,...) 回答1: DEFINE_HASHTABLE is variable's definition . For declare variable (without defining it) use DECLARE_HASHTABLE : extern DECLARE

问题 I'm trying to make a VisualStudio 2010 C program call a fastcall convention assembly routine. This is the declaration in the C code: extern boolean _fastcall InNonSuspendableCriticalRegion(DWORD); This is the declaration in the assembly code: public @InNonSuspendableCriticalRegion@4 @InNonSuspendableCriticalRegion@4 proc near ; fastcall <code> @InNonSuspendableCriticalRegion@4 endp I get the following linker error: Assembling: C:\DMS\Domains\PARLANSE\Tools\RunTimeSystem\Source\PARLANSE0.asm 1

问题 I've seen this post AngularJS best practices for module declaration? But I am still a little confused about the best way to declare and separate angularJS files for modules, controllers, services etc. I understand it is good practice to wrap controllers and services in IIFEs because it prevents them from being used out of scope. And it is good practice to separate your controllers and modules into separate files for organization. My question is, if I have a controller file myCtrl.js (function

问题 Do I need to declare all functions I use in a .c file in a header file, or can I just declare and define right there in the .c file? If so, does a definition in the .c file in this case count as the declaration also? 回答1: For the compiler, it does not matter if a declaration occurs in a .h or a .c file, because the compiler sees the preprocessed form. For the human developer reading and contributing to your code, it is much better (to avoid copy&pasting the same declaration twice) to put the

问题 I have the code: class Point3D{ protected: float x; float y; float z; public: Point3D(){x=0; y=0; z=0;} Point3D(const Point3D & point){x = point.x; y = point.y; z = point.z;} Point3D(float _x,float _y,float _z){x = _x; y = _y; z = _z;} } class Vector3D{ protected: Point3D start; Point3D end; public: ... Point3D getSizes(){ return Point3D(end-start); } } I want to create and operator+ for Point3D that will take an vector: Point3D & operator+(const Vector3D &vector){ Point3D temp; temp.x = x +