Tutorial by Examples: al

IMPORTANT: This delegate method is only called in the foreground. Swift func application(application: UIApplication, didReceiveLocalNotification notification: UILocalNotification) { } Objective-C - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotifi...

You can define implementation for specific instantiations of a template class/method. For example if you have: template <typename T> T sqrt(T t) { /* Some generic implementation */ } You can then write: template<> int sqrt<int>(int i) { /* Highly optimized integer implement...

Class methods present alternate ways to build instances of classes. To illustrate, let's look at an example. Let's suppose we have a relatively simple Person class: class Person(object): def __init__(self, first_name, last_name, age): self.first_name = first_name self.last...

public class Singleton { private static final Singleton INSTANCE = new Singleton(); private Singleton() {} public static Singleton getInstance() { return INSTANCE; } } It can be argued that this example is effectively lazy initialization. Section 12.4.1 of ...

Scalars are Perl's most basic data type. They're marked with the sigil $ and hold a single value of one of three types: a number (3, 42, 3.141, etc.) a string ('hi', "abc", etc.) a reference to a variable (see other examples). my $integer = 3; # number my $str...

To use multiple filters, separate each value with a space. HTML <img src='donald-duck.png' alt='Donald Duck' title='Donald Duck' /> CSS img { -webkit-filter: brightness(200%) grayscale(100%) sepia(100%) invert(100%); filter: brightness(200%) grayscale(100%) sepia(100%) invert(1...

Carousel components can be instantiated via jQuery with the function $('.carousel').carousel(options), where $('.carousel') is a top-level reference to the specific carousel and options is a Javascript object specifying the carousel's default attributes. The options object allows for multiple prope...

When referring to a worksheet, a range or individual cells, it is important to fully qualify the reference. For example: ThisWorkbook.Worksheets("Sheet1").Range(Cells(1, 2), Cells(2, 3)).Copy Is not fully qualified: The Cells references do not have a workbook and worksheet associated ...

Create an individual Localizable.strings file for each language. The right side would be different for each language. Think of it as a key-value pair: "str" = "str-language"; Access str in Objective-C: //Try to provide description on the localized string to be able to create...

In Python 3.x all classes are new-style classes; when defining a new class python implicitly makes it inherit from object. As such, specifying object in a class definition is a completely optional: Python 3.x3.0 class X: pass class Y(object): pass Both of these classes now contain object in ...

Ansible can be installed on CentOS or other Red Hat based systems. Firstly you should install the prerequisites: sudo yum -y update sudo yum -y install gcc libffi-devel openssl-devel python-pip python-devel then install Ansible with pip: sudo pip install ansible I can recommend for you to u...

Match any: Must match at least one string. In this example the product type must be either 'electronics', 'books', or 'video'. SELECT * FROM purchase_table WHERE product_type LIKE ANY ('electronics', 'books', 'video'); Match all (must meet all requirements). In this example both 'united...

The foreach package brings the power of parallel processing to R. But before you want to use multi core CPUs you have to assign a multi core cluster. The doSNOW package is one possibility. A simple use of the foreach loop is to calculate the sum of the square root and the square of all numbers from...

A good use of extension method is to make the language more functional Sub Main() Dim strings = { "One", "Two", "Three" } strings.Join(Environment.NewLine).Print() End Sub <Extension> Public Function Join(strings As IEnumerable(Of String), separa...

Installing linq-to-sql: Right-click the App_Code folder and then click Add New Item. The Add New Item dialog box is displayed. Under Visual Studio installed templates, select the LINQ to SQL Classes template and rename the file Tasks.dbml. Click Add. OR: Under VS2102, in your solution explorer, r...

g$ The above matches one letter (the letter g) at the end of a string in most regex engines (not in Oniguruma, where the $ anchor matches the end of a line by default, and the m (MULTILINE) modifier is used to make a . match any characters including line break characters, as a DOTALL modifier in ...

CHICKEN is a Scheme interpreter and compiler with its own extension module system called "eggs". It is capable of compiling Scheme to native code by first compiling Scheme to C. Installing Debian or Ubuntu or other derived distros: sudo apt-get install chicken-bin Fedora / RHEL / Ce...

Express JS is the goto framework for developing Web Applications, APIs and almost any kind of Backend using Node. To install express, all you have to do is run the npm command npm install express --save And you're done. To create and run a new express server create a file app.js and add this ...

Detailed instructions on getting mapbox set up or installed.

SELECT e.Fname, e.LName FROM Employees e The Employees table is given the alias 'e' directly after the table name. This helps remove ambiguity in scenarios where multiple tables have the same field name and you need to be specific as to which table you want to return data from. SELECT e.Fname,...