Tutorial by Examples: ce

Although people often say Sass as the name of this CSS-preprocessor, they often mean the SCSS-syntax. Sass uses the .sass file extension, while SCSS-Sass uses the .scss extension. They are both referred to as "Sass". Speaking generally, the SCSS-syntax is more commonly used. SCSS looks li...

Use charAt() to get a character at the specified index in the string. var string = "Hello, World!"; console.log( string.charAt(4) ); // "o" Alternatively, because strings can be treated like arrays, use the index via bracket notation. var string = "Hello, World!";...

To load a bundled image: package com.example; public class ExampleApplication { private Image getIcon() throws IOException { URL imageURL = ExampleApplication.class.getResource("icon.png"); return ImageIO.read(imageURL); } }

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...

Sometimes, you don't want to trigger metamethods, but really write or read exactly the given key, without some clever functions wrapped around the access. For this, lua provides you with raw table access methods: -- first, set up a metatable that allows no read/write access local meta = { __i...

In C# 5.0 and earlier the developer could only suppress warnings by number. With the introduction of Roslyn Analyzers, C# needs a way to disable warnings issued from specific libraries. With C# 6.0 the pragma directive can suppress warnings by name. Before: #pragma warning disable 0501 C# 6.0: ...

import std.stdio; void main() { int[] arr = [1, 2, 3, 4, 5]; auto arr2 = arr[1..$ - 1]; // .. is the slice syntax, $ represents the length of the array writeln(arr2); // [2, 3, 4] arr2[0] = 42; writeln(arr[1]); // 42 }

If you have an instance of a generic type but for some reason don't know the specific type, you might want to determine the generic arguments that were used to create this instance. Let's say someone created an instance of List<T> like that and passes it to a method: var myList = new List&lt...

SequenceEqual is used to compare two IEnumerable<T> sequences with each other. int[] a = new int[] {1, 2, 3}; int[] b = new int[] {1, 2, 3}; int[] c = new int[] {1, 3, 2}; bool returnsTrue = a.SequenceEqual(b); bool returnsFalse = a.SequenceEqual(c);

To process lists, we can simply pattern match on the constructors of the list type: listSum :: [Int] -> Int listSum [] = 0 listSum (x:xs) = x + listSum xs We can match more values by specifying a more elaborate pattern: sumTwoPer :: [Int] -> Int sumTwoPer [] = 0 sumTwoPer (x1...

Access the nth element of a list (zero-based): list = [1 .. 10] firstElement = list !! 0 -- 1 Note that !! is a partial function, so certain inputs produce errors: list !! (-1) -- *** Exception: Prelude.!!: negative index list !! 1000 -- *** Exception: Prelude.!!: inde...

private static final int REQUEST_DISCOVERABLE_BT = 2; // Unique request code private static final int DISCOVERABLE_DURATION = 120; // Discoverable duration time in seconds // 0 means always discoverable ...

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(); //...

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...

Sometimes repos will have commits that only adjust whitespace, for example fixing indentation or switching between tabs and spaces. This makes it difficult to find the commit where the code was actually written. git blame -w will ignore whitespace-only changes to find where the line really came fr...

Output can be restricted by specifying line ranges as git blame -L <start>,<end> Where <start> and <end> can be: line number git blame -L 10,30 /regex/ git blame -L /void main/, git blame -L 46,/void foo/ +offset, -offset (only for <end>) git blame -...

While RODBC is restricted to Windows computers with compatible architecture between R and any target RDMS, one of its key flexibilities is to work with Excel files as if they were SQL databases. require(RODBC) con = odbcConnectExcel("myfile.xlsx") # open a connection to the Excel file s...

Versions Release Date VersionRelease Date8.2.4December 07, 20167.53December 07, 20166.38 (unsupported)February 24, 20165.23 (unsupported)August 11, 2010 Entity types In earlier versions of Drupal, the field system was only used on content types. Now, thanks to the Entity API, we can add fields...

Problem # models.py: class Library(models.Model): name = models.CharField(max_length=100) books = models.ManyToManyField(Book) class Book(models.Model): title = models.CharField(max_length=100) # views.py def myview(request): # Query the database. libraries = Librar...

Problem Django querysets are evaluated in a lazy fashion. For example: # models.py: class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): author = models.ForeignKey(Author, related_name='books') title = models.CharField(max_length=100) ...