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To avoid verbose null checking, the ?. operator has been introduced in the language. The old verbose syntax: If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then Can be now replaced by the concise: If myObject?.Value >= 10 Then The ? operator is particularly powerful when you...

The NameOf operator resolves namespaces, types, variables and member names at compile time and replaces them with the string equivalent. One of the use cases: Sub MySub(variable As String) If variable Is Nothing Then Throw New ArgumentNullException("variable") End Sub The old sy...

This new feature makes the string concatenation more readable. This syntax will be compiled to its equivalent String.Format call. Without string interpolation: String.Format("Hello, {0}", name) With string interpolation: $"Hello, {name}" The two lines are equivalent and ...

Getting current date is very easy. You get NSDate object of current date in just single line as follows: Swift var date = NSDate() Swift 3 var date = Date() Objective-C NSDate *date = [NSDate date];

The number of seconds from the current date and time for the new date. Use a negative value to specify a date before the current date. For doing this we have a method named dateWithTimerIntervalSinceNow(seconds: NSTimeInterval) -> NSDate (Swift) or + (NSDate*)dateWithTimeIntervalSinceNow:(NSTime...

There are 4 methods for comparing dates: Swift isEqualToDate(anotherDate: NSDate) -> Bool earlierDate(anotherDate: NSDate) -> NSDate laterDate(anotherDate: NSDate) -> NSDate compare(anotherDate: NSDate) -> NSComparisonResult Objective-C - (BOOL)isEqualToDate:(NSDate *)anothe...

Dim array() As Integer = {2, 0, 1, 6} ''Initialize an array of four Integers. Dim strings() As String = {"this", "is", "an", "array"} ''Initialize an array of four Strings. Dim floats() As Single = {56.2, 55.633, 1.2, 5.7743, 22.345} ...

You may want to create a duplicate of a table: CREATE TABLE ClonedEmployees AS SELECT * FROM Employees; You can use any of the other features of a SELECT statement to modify the data before passing it to the new table. The columns of the new table are automatically created according to the selec...

Classes can be created as follow: class InputField { int maxLength; String name; } The class can be instantiated using the new keyword after which the field values will be null by default. var field = new InputField(); Field values can then be accessed: // this will trigger the sette...

<p contenteditable>This is an editable paragraph.</p> Upon clicking on the paragraph, the content of it can be edited similar to an input text field. When the contenteditable attribute is not set on an element, the element will inherit it from its parent. So all child text of a conte...

The java.math.BigInteger class provides operations analogues to all of Java's primitive integer operators and for all relevant methods from java.lang.Math. As the java.math package is not automatically made available you may have to import java.math.BigInteger before you can use the simple class nam...

Look at the contents of /etc/redhat-release cat /etc/redhat-release Here is the output from a Fedora 24 machine: Fedora release 24 (Twenty Four) As mentioned in the debian-based response, you can also use the lsb_release -a command, which outputs this from a Fedora 24 machine: LSB Version: ...

ReactJS is an open-source, component based front end library responsible only for the view layer of the application. It is maintained by Facebook. ReactJS uses virtual DOM based mechanism to fill in data (views) in HTML DOM. The virtual DOM works fast owning to the fact that it only changes individ...

<?php namespace models; use yii\db\ActiveRecord; use yii\behaviors\TimestampBehavior; class Post extends ActiveRecord { public static function tableName() { return 'post'; } public function rules() { ...

Twig is a templating language that compiles to optimized PHP code. It is primarily used for outputting HTML, but can also be used to output any other text-based format. It is a standalone component that can be easily integrated into any PHP project. It provides many excellent features: Autoescap...

You have to keep the operator precedence in mind when using await keyword. Imagine that we have an asynchronous function which calls another asynchronous function, getUnicorn() which returns a Promise that resolves to an instance of class Unicorn. Now we want to get the size of the unicorn using th...

The Oracle SQL and PL/SQL || operator allows you to concatenate 2 or more strings together. Example: Assuming the following customers table: id firstname lastname --- ----------- ---------- 1 Thomas Woody Query: SELECT firstname || ' ' || lastname || ' is in my database.' a...

Prerequisites Installation

// Integral types as hex string.Format("Hexadecimal: byte2: {0:x2}; byte4: {0:X4}; char: {1:x2}", 123, (int)'A'); // Integers with thousand separators string.Format("Integer, thousand sep.: {0:#,#}; fixed length: >{0,10:#,#}<", 1234567); // Integer with leading zero...

Use existing .NET classes instantly with PowerShell by using [class]::Method(args): PS C:\> [guid]::NewGuid() Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31bc Similarly, in PowerShell 5+ you may use the New-Guid cmdlet: PS C:\> New-Guid Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31...