Tutorial by Examples: io

An enumeration is a user-defined data type consists of integral constants and each integral constant is given a name. Keyword enum is used to define enumerated data type. If you use enum instead of int or string/ char*, you increase compile-time checking and avoid errors from passing in invalid con...

It is usually not a good idea to mix signed and unsigned integers in arithmetic operations. For example, what will be output of following example? #include <stdio.h> int main(void) { unsigned int a = 1000; signed int b = -1; if (a > b) puts("a is more than b&quot...

There are multiple ways to set a key's object in an NSDictionary, corresponding to the ways you get a value. For instance, to add a lamborghini to a list of cars Standard [cars setObject:lamborghini forKey:@"Lamborghini"]; Just like any other object, call the method of NSDictionary th...

There are multiple ways to get an object from an NSDictionary with a key. For instance, to get a lamborghini from a list of cars Standard Car * lamborghini = [cars objectForKey:@"Lamborghini"]; Just like any other object, call the method of NSDictionary that gives you an object for a ...

Represents a thread-safe collection of key/value pairs that can be accessed by multiple threads concurrently. Creating an instance Creating an instance works pretty much the same way as with Dictionary<TKey, TValue>, e.g.: var dict = new ConcurrentDictionary<int, string>(); Ad...

Defining a method in Ruby 2.x returns a symbol representing the name: class Example puts def hello end end #=> :hello This allows for interesting metaprogramming techniques. For instance, methods can be wrapped by other methods: class Class def logged(name) original_method...

You can use a For Each...Next loop to iterate through any IEnumerable type. This includes arrays, lists, and anything else that may be of type IEnumerable or returns an IEnumerable. An example of looping through a DataTable's Rows property would look like this: For Each row As DataRow In DataTable...

Detailed instructions on getting database set up or installed.

If you want to import a module that doesn't already exist as a built-in module in the Python Standard Library nor as a side-package, you can do this by adding the path to the directory where your module is found to sys.path. This may be useful where multiple python environments exist on a host. im...

A basic custom element is created in Aurelia based on naming conventions, by simply adding the suffix CustomElement to the name of a class. This suffix will automatically be stripped out by Aurelia. The remaining part of the class name will be lowercased and separated using a hyphen and can then be ...

Let's suppose we have a reference to the JQuery type definition and we want to extend it to have additional functions from a plugin we included and which doesn't have an official type definition. We can easily extend it by declaring functions added by plugin in a separate interface declaration with ...

You can open a connection (i.e. request one from the pool) using a context manager: with engine.connect() as conn: result = conn.execute('SELECT price FROM products') for row in result: print('Price:', row['price']) Or without, but it must be closed manually: conn = engine.co...

If you only want to execute a single statement, you can use the engine directly and it will open and close the connection for you: result = engine.execute('SELECT price FROM products') for row in result: print('Price:', row['price'])

You can use engine.begin to open a connection and begin a transaction that will be rolled back if an exception is raised, or committed otherwise. This is an implicit way of using a transaction, since you don't have the option of rolling back manually. with engine.begin() as conn: conn.execute(...

In Android there is a default options menu, which can take a number of options. If a larger number of options needs to be displayed, then it makes sense to group those options in order to maintain clarity. Options can be grouped by putting dividers (i.e. horizontal lines) between them. In order to a...

Detailed instructions on getting mvvmcross set up or installed.

Detailed instructions on getting resharper set up or installed.

If you need to get a specific language or version of an item, you can use these overloads of GetItem() Sitecore.Context.Database.GetItem("/sitecore/content/Sitecore", Language.Current, new Version(5));

Install JDK 8 (Windows, Linux) and set the path (Windows). Install Scala (Linux), For Windows visit http://www.scala-lang.org/download/ download and install binary distribution, set the environment variable for scala in PATH which is in \scala\bin. Installing Typesafe activator (It contains Scal...

To ensure encapsulation, member variables of a class should be private and only be accessible to public via public get/set access methods. It is a common practice to prefix private fields with _ public class Person { private var _name:String = ""; public function get name():S...