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The below examples use the new form API introduced in RC3. pw-change.template.html <form class="container" [formGroup]="pwChangeForm"> <label for="current">Current Password</label> <input id="current" formControlName="curr...

In Java, there is a built-in language-level locking mechanism: the synchronized block, which can use any Java object as an intrinsic lock (i.e. every Java object may have a monitor associated with it). Intrinsic locks provide atomicity to groups of statements. To understand what that means for us, ...

An atomic operation is an operation that is executed "all at once", without any chance of other threads observing or modifying state during the atomic operation's execution. Lets consider a BAD EXAMPLE. private static int t = 0; public static void main(String[] args) { ExecutorSe...

Press Ctrl + v to enter into visual block mode. Use ↑ / ↓ / j / k to select multiple lines. Press Shift + i and start typing what you want. After you press Esc, the text will be inserted into all the lines you selected. Remember that Ctrl+c is not 100% equivalent to Esc and will not work in this...

In order to work with bindings in WPF, you need to define a DataContext. The DataContext tells bindings where to get their data from by default. <Window x:Class="StackOverflowDataBindingExample.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation&q...

The Django template system has built-in tags and filters, which are functions inside template to render content in a specific way. Multiple filters can be specified with pipes and filters can have arguments, just as in variable syntax. {{ "MAINROAD 3222"|lower }} # mainroad 3222 {{ 10...

If you need to add an attribute through razor that has a - (hyphen) in the name you cannot simply do @Html.DropDownListFor(m => m.Id, Model.Values, new { @data-placeholder = "whatever" }) it will not compile. data-* attributes are valid and common in html5 for adding extra values t...

The official style guide is located on the homepage and generally goes for: readability (instead of compactness) ease of modification clean diffs This means that, for example, this: homeDirectory : String homeDirectory = "/root/files" evaluate : Boolean -> Bool evalua...

The random() function can be used to generate pseudo-random numbers: void setup() { Serial.begin(9600); } void loop() { long randomNumber = random(500); // Generate a random number between 0 and 499 Serial.println(randomNumber); randomNumber = random(100, 1000); // Genera...

composer update composer update will update our dependencies as they are specified in composer.json. For example, if our project uses this configuration: "require": { "laravelcollective/html": "2.0.*" } Supposing we have actually installed the 2.0.1 version ...

Below are the operators that can be overloaded in classes, along with the method definitions that are required, and an example of the operator in use within an expression. N.B. The use of other as a variable name is not mandatory, but is considered the norm. OperatorMethodExpression+ Addition__add...

ABAP Classes can be declared Globally or Locally. A global class can be used by any object within the ABAP repository. By contrast, a local class can only be used within the scope it is declared. CLASS lcl_abap_class DEFINITION. PUBLIC SECTION. PROTECTED SECTION. PRIVATE SECTION. ENDCLASS...

Controls that can be bound with data can make use of SqlDataSource controls. The SqlDataSource control not only allows you to retrieve data from a database, but also edit and sort the data. Retrieving Data Stored Procedure: <asp:SqlDataSource ID="SqlDataSourceEmployees" runat=&q...

You can add an interpreter directive (shebang) to your script. Create a file called hello_world.rb which contains: #!/usr/bin/env ruby puts 'Hello World!' Give the script executable permissions. Here's how to do that in Unix: $ chmod u+x hello_world.rb Now you do not need to call the Ru...

A single case discriminated union is like any other discriminated union except that it only has one case. // Define single-case discriminated union type. type OrderId = OrderId of int // Construct OrderId type. let order = OrderId 123 // Deconstruct using pattern matching. // Parentheses used...

These are the most common ways to create an instance of Guid: Creating an empty guid (00000000-0000-0000-0000-000000000000): Guid g = Guid.Empty; Guid g2 = new Guid(); Creating a new (pseudorandom) Guid: Guid g = Guid.NewGuid(); Creating Guids with a specific value: Guid g = n...

let x = true match x with | true -> printfn "x is true" yields a warning C:\Program Files (x86)\Microsoft VS Code\Untitled-1(2,7): warning FS0025: Incomplete pattern matches on this expression. For example, the value 'false' may indicate a case not covered by the pattern(s). ...

Incorrect usage: In the following snippet, the last match will never be used: let x = 4 match x with | 1 -> printfn "x is 1" | _ -> printfn "x is anything that wasn't listed above" | 4 -> printfn "x is 4" prints x is anything that wasn't listed abov...

Returns a string that represents the unqualified name of a variable, type, or member. int counter = 10; nameof(counter); // Returns "counter" Client client = new Client(); nameof(client.Address.PostalCode)); // Returns "PostalCode" The nameof operator was introduced in C# ...

>>> code = """for i in range(5):\n print('Hello world!')""" >>> exec(code) Hello world! Hello world! Hello world! Hello world! Hello world!