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Stream operations fall into two main categories, intermediate and terminal operations, and two sub-categories, stateless and stateful. Intermediate Operations: An intermediate operation is always lazy, such as a simple Stream.map. It is not invoked until the stream is actually consumed. This can...

Find a document with the property { greetings: 'Hellu' } and change it to { greetings: 'Whut?' } const MongoClient = require('mongodb').MongoClient; const url = 'mongodb://localhost:27017/test'; MongoClient.connect(url, function (err, db) { if (err) throw new Error(err); db.collecti...

You can use the plus (+) operator to concatenate strings: 'Dart ' + 'is ' + 'fun!'; // 'Dart is fun!' You can also use adjacent string literals for concatenation: 'Dart ' 'is ' 'fun!'; // 'Dart is fun!' You can use ${} to interpolate the value of Dart expressions within strings. The curly...

We are so used to the name D3.js that it's possible to forget that D3 is actually DDD (Data-Driven Documents). And that's what D3 does well, a data-driven approach to DOM (Document Object Model) manipulation: D3 binds data to DOM elements and manipulates those elements based on the bounded data. Le...

git log --pretty=format:"%Cgreen%ci %Cblue%cn %Cgreen%cr%Creset %s" This will give a nice overview of all commits (1 per line) with date, user and commit message. The --pretty option has many placeholders, each starting with %. All options can be found here

It is not possible to add and commit an empty folder in Git due to the fact that Git manages files and attaches their directory to them, which slims down commits and improves speed. To get around this, there are two methods: Method one: .gitkeep One hack to get around this is to use a .gitkeep fil...

Use Spliterators.spliterator() or Spliterators.spliteratorUnknownSize() to convert an iterator to a stream: Iterator<String> iterator = Arrays.asList("A", "B", "C").iterator(); Spliterator<String> spliterator = Spliterators.spliteratorUnknownSize(itera...

To initialize a static final fields that require using more than a single expression, a static initializer can be used to assign the value. The following example initializes a unmodifiable set of Strings: public class MyClass { public static final Set<String> WORDS; static {...

Orthogonal to the JRE versus JDK dichotomy, there are two types of Java release that are widely available: The Oracle Hotspot releases are the ones that you download from the Oracle download sites. The OpenJDK releases are the ones that are built (typically by third-party providers) from the Ope...

A JDK installation and a text editor are the bare minimum for Java development. (It is nice to have a text editor that can do Java syntax highlighting, but you can do without.) However for serious development work it is recommended that you also use the following: A Java IDE such as Eclipse, In...

The format statement applies the given format to the specified variable for display purposes only, i.e. the underlying value does not change. data example1 ; Date = '02AUG2016'd ; /* stored as a SAS date, i.e. a number */ Date2 = '31AUG2016'd ; format Date monyy7. Date2 yymmddn8. ; run...

Adjustments can be done for specific platforms from C# code, for example for changing padding for all the targeted platforms. if (Device.OS == TargetPlatform.iOS) { panel.Padding = new Thickness (10); } else { panel.Padding = new Thickness (20); } An helper method is also availab...

To mark some expression as an abbreviation, use <abbr> tag: <p>I like to write <abbr title="Hypertext Markup Language">HTML</abbr>!</p> If present, the title attribute is used to present the full description of such abbreviation.

Assume you want to delegate to a class but you do not want to provide the delegated-to class in the constructor parameter. Instead, you want to construct it privately, making the constructor caller unaware of it. At first this might seem impossible because class delegation allows to delegate only to...

Struct defines new classes with the specified attributes and accessor methods. Person = Struct.new :first_name, :last_name You can then instantiate objects and use them: person = Person.new 'John', 'Doe' # => #<struct Person first_name="John", last_name="Doe"> p...

Attributes can be accessed strings and symbols as keys. Numerical indexes also work. Person = Struct.new :name alice = Person.new 'Alice' alice['name'] # => "Alice" alice[:name] # => "Alice" alice[0] # => "Alice"

The first thing to do is to add the service to AndroidManifest.xml, inside the <application> tag: <application ...> ... <service android:name=".RecordingService" <!--"enabled" tag specifies Whether or not the service can ...

Any list comprehension can be correspondingly coded with list monad's do notation. [f x | x <- xs] f <$> xs do { x <- xs ; return (f x) } [f x | f <- fs, x <- xs] fs <*> xs do { f <- fs ; x <- xs ; return (f x) } [y | x &...

Let us first create a simple .proto file person.proto package Protocol; message Person { required string firstName = 1; required string lastName = 2; optional int32 age = 3; } After saving we can now create the Haskell files which we can use in our project by running ...

Sometimes you want an installation without anything except the bare minimum phoenix setup. The follow command will give you that. mix phoenix.new web --no-brunch --no-ecto Note: You must have installed Elixir, Erlang, Hex, Mix and the Phoenix archive for skeleton installation