Tutorial by Examples: nd

You can use the Substring method to get any number of characters from a string at any given location. However, if you only want a single character, you can use the string indexer to get a single character at any given index like you do with an array: string s = "hello"; char c = s[1]; //...

When you need to pass a collection into a Java method: import scala.collection.JavaConverters._ val scalaList = List(1, 2, 3) JavaLibrary.process(scalaList.asJava) If the Java code returns a Java collection, you can turn it into a Scala collection in a similar manner: import scala.collectio...

A metatable defines a set of operations which alter the behaviour of a lua object. A metatable is just an ordinary table, which is used in a special way. local meta = { } -- create a table for use as metatable -- a metatable can change the behaviour of many things -- here we modify the 'tostrin...

Perhaps the most important use of metatables is the possibility to change the indexing of tables. For this, there are two actions to consider: reading the content and writing the content of the table. Note that both actions are only triggered if the corresponding key is not present in the table. Re...

To create a background session // Swift: let mySessionID = "com.example.bgSession" let bgSessionConfig = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(mySessionID) let session = NSURLSession(configuration: bgSessionConfig) // add tasks here //...

Ionic Framework A Cross-platform mobile application development framework using Angular JS and Front End web technologies. Official website: http://ionicframework.com/ Documentation: http://ionicframework.com/docs/ Installation and Setup Installation Ionic required NPM(Node Package Manager) an...

import std.stdio; void main() { int[] arr = [1, 2, 3, 4]; writeln(arr.length); // 4 writeln(arr[2]); // 3 // type inference still works auto arr2 = [1, 2, 3, 4]; writeln(typeof(arr2).stringof); // int[] }

Sent to a window procedure when: the user selects an item from a menu a control sends a notification to its parent window an accelerator keystroke is translated Message SourceHIWORD(wp)LOWORD(wp)lpMenu0Menu ID (IDM_*)0Accelerator1Accel ID (IDM_*)0Controlnotification codeControl idHWND of con...

When you have an input with well defined boundaries and are expecting more than one match in your string, you have two options: Using lazy quantifiers; Using a negated character class. Consider the following: You have a simple templating engine, you want to replace substrings like $[foo] whe...

pip doesn't current contain a flag to allow a user to update all outdated packages in one shot. However, this can be accomplished by piping commands together in a Windows environment: for /F "delims= " %i in ('pip list --outdated --local') do pip install -U %i This command takes all pa...

To make artisan migrate a fresh database before running tests, use DatabaseMigrations. Also if you want to avoid middleware like Auth, use WithoutMiddleware. <?php use Illuminate\Foundation\Testing\WithoutMiddleware; use Illuminate\Foundation\Testing\DatabaseMigrations; class ExampleTest ...

You can use all() to determine if all the values in an iterable evaluate to True nums = [1, 1, 0, 1] all(nums) # False chars = ['a', 'b', 'c', 'd'] all(chars) # True Likewise, any() determines if one or more values in an iterable evaluate to True nums = [1, 1, 0, 1] any(nums) # True val...

Declare a BluetoothAdapter first. BluetoothAdapter mBluetoothAdapter; Now create a BroadcastReceiver for ACTION_FOUND private final BroadcastReceiver mReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String action = intent.getAction(); //...

A list of recognised color keyword names can be found in the W3C Recommendation for SVG. <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <circle r="30" cx="100" cy="100" fill="red" stroke=&qu...

Count returns the number of elements in an IEnumerable<T>. Count also exposes an optional predicate parameter that allows you to filter the elements you want to count. int[] array = { 1, 2, 3, 4, 2, 5, 3, 1, 2 }; int n = array.Count(); // returns the number of elements in the array int x ...

To search for a string inside a string, there are several functions: indexOf( searchString ) and lastIndexOf( searchString ) indexOf() will return the index of the first occurrence of searchString in the string. If searchString is not found, then -1 is returned. var string = "Hello, World!&q...

A random forest is a meta estimator that fits a number of decision tree classifiers on various sub-samples of the dataset and use averaging to improve the predictive accuracy and control over-fitting. A simple usage example: Import: from sklearn.ensemble import RandomForestClassifier Define tr...

Python has a variety of command-line switches which can be passed to py. These can be found by performing py --help, which gives this output on Python 3.4: Python Launcher usage: py [ launcher-arguments ] [ python-arguments ] script [ script-arguments ] Launcher arguments: -2 : Launch ...

Postfix increment X++ will add 1 to x var x = 42; x++; Console.WriteLine(x); // 43 Postfix decrement X-- will subtract one var x = 42 x--; Console.WriteLine(x); // 41 ++x is called prefix increment it increments the value of x and then returns x while x++ returns the value of x and the...

vagrant up --provider docker