Tutorial by Examples: f

using System; using System.Threading; using System.Threading.Tasks; class Program { static void Main( string[] args ) { object sync = new object(); int sum = 0; Parallel.For( 1, 1000, ( i ) => { lock( sync ) sum = sum + i; // lock is necessa...

Using the Library Database, we try to find the last book added to the database for each author. For this simple example we assume an always incrementing Id for each record added. SELECT MostRecentBook.Name, MostRecentBook.Title FROM ( SELECT Authors.Name, Books.Title, ...

As of Qt 5.1 and later you can use QQmlApplicationEngine instead of QQuickView to load and render a QML script. With QQmlApplicationEngine you do need to use a QML Window type as your root element. You can obtain the root context from the engine where you can then add global properties to the cont...

class ClassWithAReallyLongName { public: class Iterator { /* ... */ }; Iterator end(); }; Defining the member end with a trailing return type: auto ClassWithAReallyLongName::end() -> Iterator { return Iterator(); } Defining the member end without a trailing return type: Clas...

>>> df ID Year Jan_salary Feb_salary Mar_salary 0 1 2016 4500 4200 4700 1 2 2016 3800 3600 4400 2 3 2016 5500 5200 5300 >>> melted_df = pd.melt(df,id_vars=['ID','Year'], v...

Example for searching just one user with a specific id, you should do: $options = ['limit' => 1]; $filter = ['_id' => new \MongoDB\BSON\ObjectID('578ff7c3648c940e008b457a')]; $query = new \MongoDB\Driver\Query($filter, $options); $cursor = $manager->executeQuery('database_name.collect...

Example for searching multiple users with the name "Mike": $filter = ['name' => 'Mike']; $query = new \MongoDB\Driver\Query($filter); $cursor = $manager->executeQuery('database_name.collection_name', $query); foreach ($cursor as $doc) { var_dump($doc); }

Using range-base loops, you can loop over a sub-part of a given container or other range by generating a proxy object that qualifies for range-based for loops. template<class Iterator, class Sentinel=Iterator> struct range_t { Iterator b; Sentinel e; Iterator begin() const { return ...

First create a resource pool besides the default one CREATE RESOURCE POOL [PoolAdhoc] WITH(min_cpu_percent=0, max_cpu_percent=50, min_memory_percent=0, max_memory_percent=50) GO Create the worload group for the pool CREATE WORKLOAD GROUP [AdhocMedium] WITH(importa...

Sometimes specific instances of data should be used. Recreation is not desired and referencing static data would have a code smell. It is possible to specify a XmlAdapter instance the Unmarshaller should use, which allows the user to use XmlAdapters with no zero-arg constructor and/or pass data to ...

Multiple fields can be specified for the ORDER BY clause, in either ASCending or DESCending order. For example, using the http://stackoverflow.com/documentation/sql/280/example-databases/1207/item-sales-table#t=201607211314066434211 table, we can return a query that sorts by SaleDate in ascending o...

ARC can be disabled for individual files by adding the -fno-objc-arc compiler flag for each file. Conversely it can be added in Targets ▸ Build Phases ▸ Compile Sources

Repeated Timer event Swift class ViewController: UIViewController { var timer = NSTimer() override func viewDidLoad() { NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector(self.timerMethod()), userInfo: nil, repeats: true) } func tim...

All parameters specified after the first asterisk in the function signature are keyword-only. def f(*a, b): pass f(1, 2, 3) # TypeError: f() missing 1 required keyword-only argument: 'b' In Python 3 it's possible to put a single asterisk in the function signature to ensure that the rema...

Usually grep prints only matching lines. In the example below seq 9 generates a list of numbers from 1 to 9, one per line, and grep prints a single matching line: seq 9 | grep 5 # 5 The -C n option (or --context=n in long form) prints n lines before and after each matching line, in addition to ...

import std.stdio; bool isPrime(int number) { foreach(i; 2..number) { if (number % i == 0) { return false; } } return true; } void main() { writeln(2.isPrime); writeln(3.isPrime); writeln(4.isPrime); 5.isPrime.writeln; } ...

On calling, an application chooser dialog will appear and by selecting an application you can share your content with it. For calling use this line of code in your program class: share(context, "This is a test message", "Test Subject") Function's definition: public static v...

Notice, that in order to change file prmissions, your device need to be rooted, su binary doesn't come with factory shipped devices! Convention: adb shell su -c "chmod <numeric-permisson> <file>" Numeric permission constructed from user, group and world sections. For exa...

Dim openListType = GetType(List(Of )) Dim typeParameters = {GetType(String)} Dim stringListType = openListType.MakeGenericType(typeParameters) Dim instance = DirectCast(Activator.CreateInstance(stringListType), List(Of String)) instance.Add("Hello")

Timing There are two trigger action time modifiers : BEFORE trigger activates before executing the request, AFTER trigger fire after change. Triggering event There are three events that triggers can be attached to: INSERT UPDATE DELETE Before Insert trigger example DELIMITER $$ ...