async.waterfall(tasks, afterTasksCallback) will execute a set of tasks. Each task are executed after another, and the result of a task is passed to the next task. As async.series(), if a task fails, async stop the execution and call immediately the main callback.
When tasks are finished successfull...
Dropping the database is a simple one-liner statement. Drop database will delete the database, hence always ensure to have a backup of the database if required.
Below is the command to drop Employees Database
DROP DATABASE [dbo].[Employees]
SELECT name, caption as title, year, pages FROM books
UNION
SELECT name, title, year, 0 as pages FROM movies
When combining 2 record sets with different columns then emulate the missing ones with default values.
extern int var;
static int var; /* Undefined behaviour */
C11, §6.2.2, 7 says:
If, within a translation unit, the same identifier appears with both
internal and external linkage, the behavior is undefined.
Note that if an prior declaration of an identifier is visible then it'll have the pri...
Use the yum command to manage packages in Enterprise Linux-based operating systems:
yum install php
This installs a minimal install of PHP including some common features. If you need additional modules, you will need to install them separately. Once again, you can use yum to search for these pac...
Note:
There will be some Objective-c in this example..
We will make a wrapper to C++ in this example, So don't worry to much about it.
First start Xcode and create a project.
And select a Cocoa application
Delete all sources except the Info.plist file.(Your app won't work without it)
Creat...
You should always use <?php ?> tags or short-echo tags <?= ?>. Other variations (in particular, short tags <? ?>) should not be used as they are commonly disabled by system administrators.
When a file is not expected to produce output (the entire file is PHP code) the closing ?>...
You can use the header() function to instruct the browser to redirect to a different URL:
$url = 'https://example.org/foo/bar';
if (!headers_sent()) { // check headers - you can not send headers if they already sent
header('Location: ' . $url);
exit; // protects from code being executed afte...
Customizing the Shell prompt
Default command prompt can be changed to look different and short. In case the current directory is long default command prompt becomes too large. Using PS1 becomes useful in these cases. A short and customized command pretty and elegant. In the table below PS1 has be...
#include <Windows.h>
DWORD WINAPI DoStuff(LPVOID lpParameter)
{
// The new thread will start here
return 0;
}
int main()
{
// Create a new thread which will start at the DoStuff function
HANDLE hThread = CreateThread(
NULL, // Thread attributes
...
Improper Inheritance
Lets say there are 2 classes class Foo and Bar. Foo has two features Do1 and Do2. Bar needs to use Do1 from Foo, but it doesn't need Do2 or needs feature that is equivalent to Do2 but does something completely different.
Bad way: make Do2() on Foo virtual then override it in B...
One of Angular's strength's is client-side form validation.
Dealing with traditional form inputs and having to use interrogative jQuery-style processing can be time-consuming and finicky. Angular allows you to produce professional interactive forms relatively easily.
The ng-model directive provide...
uses
System.Character;
var
S1, S2: string;
begin
S1 := 'Foo';
S2 := ToLower(S1); // Convert the string to lower-case
S1 := ToUpper(S2); // Convert the string to upper-case
The assignment operator = sets thr left hand operand's value to the value of right hand operand, and return that value:
int a = 3; // assigns value 3 to variable a
int b = a = 5; // first assigns value 5 to variable a, then does the same for variable b
Console.WriteLine(a = 3 + 4); // prints ...
The echo setting determines whether command echoing is on or off. This is what a sample program looks like with command echoing on (default):
C:\Windows\System32>echo Hello, World!
Hello, World!
C:\Windows\System32>where explorer
C:\Windows\System32\explorer.exe
C:\Windows\System32>...
Sometimes you may need additional features from a directive. Instead of rewriting (copy) the directive, you can modify how the directive behaves.
The decorator will be executed during $inject phase.
To do so, provde a .config to your module.
The directive is called myDirective, so you have to con...
Angular js directives can be nested or be made interoperable.
In this example, directive Adir exposes to directive Bdir it's controller $scope, since Bdir requires Adir.
angular.module('myApp',[]).directive('Adir', function () {
return {
restrict: 'AE',
controlle...
enum Util {
/* No instances */;
public static int clamp(int min, int max, int i) {
return Math.min(Math.max(i, min), max);
}
// other utility methods...
}
Just as enum can be used for singletons (1 instance classes), it can be used for utility classes (0 instance...
Imagine that we have a class Math.php with logic of calculating of fiobanacci and factorial numbers. Something like this:
<?php
class Math {
public function fibonacci($n) {
if (is_int($n) && $n > 0) {
$elements = array();
$elements[1] = 1;
...
install the required Microsoft.SqlServer.Types assembly; they are not installed by default, and are available from Microsoft here as "Microsoft® System CLR Types for Microsoft® SQL Server® 2012" - note that there are separate installers for x86 and x64.
install Dapper.EntityFramew...
