Tutorial by Examples: v

Although not traditionally considered loops, the @goto and @label macros can be used for more advanced control flow. One use case is when the failure of one part should lead to the retry of an entire function, often useful in input validation: function getsequence() local a, b @label start ...

This example will show you how you can resolve data fetched from a service before rendering your application's view. Uses angular/router 3.0.0-beta.2 at the time of writing users.service.ts ... import { Http, Response } from '@angular/http'; import { Observable } from 'rxjs/Rx'; import { User ...

Structured Query Language (SQL) is a special-purpose programming language designed for managing data held in a Relational Database Management System (RDBMS). SQL-like languages can also be used in Relational Data Stream Management Systems (RDSMS), or in "not-only SQL" (NoSQL) databases. ...

in this way '0' representing the known values ​​are ranked first, '1' representing the NULL values ​​are sorted by the last: SELECT ID ,REGION ,CITY ,DEPARTMENT ,EMPLOYEES_NUMBER FROM DEPT ORDER BY CASE WHEN REGION IS NULL THEN 1 ELSE 0 END, REGION ...

If you need to send events from fragment to activity, one of the possible solutions is to define callback interface and require that the host activity implement it. Example Send callback to an activity, when fragment's button clicked First of all, define callback interface: public interface Samp...

Recursive type Discriminated unions can be recursive, that is they can refer to themselves in their definition. The prime example here is a tree: type Tree = | Branch of int * Tree list | Leaf of int As an example, let's define the following tree: 1 2 5 3 4 We can defi...

Even experienced Java developers tend to think that Java has only three protection modifiers. The language actually has four! The package private (a.k.a. default) level of visibility is often forgotten. You should pay attention to what methods you make public. The public methods in an application a...

ASP.NET Core introduces the concept of dependency injection into Views via the @inject directive via the following syntax : @inject <type> <name> Example Usage Adding this directive into your View will basically generate a property of the given type using the given name within your ...

Amp harnesses Promises [another name for Awaitables] and Generators for coroutine creation. require __DIR__ . '/vendor/autoload.php'; use Amp\Dns; // Try our system defined resolver or googles, whichever is fastest function queryStackOverflow($recordtype) { $requests = [ Dns\qu...

In vc.h @interface vc : UIViewController<UIWebViewDelegate> in vc.m - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{ if (navigationType == UIWebViewNavigationTypeLinkClicked){...

For Each row As DataRow In FooDataTable.Rows Me.RowsToProcess.Add(row) Next Dim myOptions As ParallelOptions = New ParallelOptions() myOptions.MaxDegreeOfParallelism = environment.processorcount Parallel.ForEach(RowsToProcess, myOptions, Sub(currentRow, state) ...

Of the LINQ methods which use deferred execution, some require a single value to be evaluated at a time. The following code: var lst = new List<int>() {3, 5, 1, 2}; var streamingQuery = lst.Select(x => { Console.WriteLine(x); return x; }); foreach (var i in streamingQuery) { ...

When a function doesn't preserve units automatically due to lower-level operations, the LanguagePrimitives module can be used to set units on the primitives that support them: /// This cast preserves units, while changing the underlying type let inline castDoubleToSingle (x : float<'u>) : fl...

The volatile modifier is used in multi threaded programming. If you declare a field as volatile it is a signal to threads that they must read the most recent value, not a locally cached one. Furthermore, volatile reads and writes are guaranteed to be atomic (access to a non-volatile long or double i...

This example shows how to establish a connection to an SSL-enabled POP3 email server and send a simple (text only) email. // Configure mail provider Properties props = new Properties(); props.put("mail.smtp.host", "smtp.mymailprovider.com"); props.put("ma...

Once you've installed the .NET CLI tools, you can create a new project with the following command: dotnet new --lang f# This creates a command line program.

How to get the average amount of debit and credit transactions? > db.transactions.aggregate( [ { $group : { _id : '$cr_dr', // group by type of transaction (debit or credit) count : {$sum : 1}, // number of transaction for each type...

In functional programming languages like F# null values are considered potentially harmful and poor style (non-idiomatic). Consider this C# code: string x = SomeFunction (); int l = x.Length; x.Length will throw if x is null let's add protection: string x = SomeFunction (); int l = x ...

Active Patterns can be used to make calling some .NET API's feel more natural, particularly those that use an output parameter to return more than just the function return value. For example, you'd normally call the System.Int32.TryParse method as follows: let couldParse, parsedInt = System.Int32....

UITextView has extra paddings by default. Sometimes it's annoying especially if you want to measure some text without view instance and place them at some area precisely. Do this to remove such paddings. messageTextView.textContainerInset = UIEdgeInsetsZero messageTextView.textContainer.lineFragm...