Tutorial by Examples: d

The next example can be used to determine whether a enumeration has the FlagsAttribute specified. The methodology used is based on Reflection. This example will give a True result: Dim enu As [Enum] = New FileAttributes() Dim hasFlags As Boolean = enu.GetType().GetCustomAttributes(GetType(FlagsAt...

The next example is intended to count the amount of flags in the specified flag combination. The example is provided as a extension method: <DebuggerStepThrough> <Extension> <EditorBrowsable(EditorBrowsableState.Always)> Public Function CountFlags(ByVal sender As [Enum]) As In...

The next code illustrates how to find the nearest value of a Enum. First we define this Enum that will serve to specify search criteria (search direction) Public Enum EnumFindDirection As Integer Nearest = 0 Less = 1 LessOrEqual = 2 Greater = 3 GreaterOrEqual = 4 End Enum...

There are a number of guidelines to follow when creating and using header files in a C project: Idemopotence If a header file is included multiple times in a translation unit (TU), it should not break builds. Self-containment If you need the facilities declared in a header file, you sh...

If a particular header file is included more than once in a translation unit (TU), there should not be any compilation problems. This is termed 'idempotence'; your headers should be idempotent. Think how difficult life would be if you had to ensure that #include <stdio.h> was only included ...

Google's Include What You Use project, or IWYU, ensures source files include all headers used in the code. Suppose a source file source.c includes a header arbitrary.h which in turn coincidentally includes freeloader.h, but the source file also explicitly and independently uses the facilities from ...

The C standard says that there is very little difference between the #include <header.h> and #include "header.h" notations. [#include <header.h>] searches a sequence of implementation-defined places for a header identified uniquely by the specified sequence between the &l...

If a singleshot timer is required, it is quiet handy to have the slot as lambda function right in the place where the timer is declared: QTimer::singleShot(1000, []() { /*Code here*/ } ); Due to this Bug (QTBUG-26406), this is way is only possible since Qt5.4. In earlier Qt5 versions it has to ...

Setup First, install the necessary packages with: npm install express cors mongoose Code Then, add dependencies to server.js, create the database schema and the name of the collection, create an Express.js server, and connect to MongoDB: var express = require('express'); var cors = require('...

passwd

Run the following as root: passwd username

Run the following as root: useradd username

Run the following as root: userdel -r username

This can be useful if you're writing a game or something that needs to execute a piece of code every a few seconds. import android.os.Handler; public class Timer { private Handler handler; private boolean paused; private int interval; private Runnable task = new Runnable ...

// World physics self.physicsWorld.gravity = CGVectorMake(0, -9.8);

Firstly, we set node category let groundBody: UInt32 = 0x1 << 0 let boxBody: UInt32 = 0x1 << 1 Then add Ground type node and Box type node. let ground = SKSpriteNode(color: UIColor.cyanColor(), size: CGSizeMake(self.frame.width, 50)) ground.position = CGPointMake(CGRectGetMidX(sel...

Set scene as delegate //set your scene as SKPhysicsContactDelegate class yourScene: SKScene, SKPhysicsContactDelegate self.physicsWorld.contactDelegate = self; Then you have to implement one or the other of the contact functions: optional func didBegin(contact:) and/or optional fund didEnd...

MSBuild evaluates PropertyGroup, Choose and ItemGroup elements that are directly under the Project element before those that are in Target elements. Directly under the Project element, PropertyGroup and Choose elements are evaluated in the order in which they appear, and then ItemGroup elements a...

=SUMPRODUCT(IF(FREQUENCY(MATCH(A1:A100,A1:A100,0),MATCH(A1:A100,A1:A100,0))>0,1))

add_action( 'init', function() { // do something here } ); Using a function block to hook a set of instructions. With the init hook, the set of instructions will be executed right after wordpress has finished loading the necessary components.