Tutorial by Examples: d

A class method is called on the class the method belongs to, not an instance of it. This is possible because Objective-C classes are also objects. To denote a method as a class method, change the - to a +: + (void)hello { NSLog(@"Hello World"); }

Calling an instance method: [classInstance hello]; @interface Sample -(void)hello; // exposing the class Instance method @end @implementation Sample -(void)hello{ NSLog(@"hello"); } @end Calling an instance method on the current instance: [self hell...

A Broadcast receiver is an Android component which allows you to register for system or application events. A receiver can be registered via the AndroidManifest.xml file or dynamically via the Context.registerReceiver() method. public class MyReceiver extends BroadcastReceiver { @Override ...

nuget sources add -name feedname -source http://sourcefeedurl

Unlike C++ in C# you can call a virtual method from class constructor (OK, you can also in C++ but behavior at first is surprising). For example: abstract class Base { protected Base() { _obj = CreateAnother(); } protected virtual AnotherBase CreateAnother() { ...

To add a method to a button, first create an action method: Objective-C -(void)someButtonAction:(id)sender { // sender is the object that was tapped, in this case its the button. NSLog(@"Button is tapped"); } Swift func someButtonAction() { print("Button is tapped...

To find all the files of a certain extension within the current path you can use the following find syntax. It works by making use of bash's built-in glob construct to match all the names having the .extension. find /directory/to/search -maxdepth 1 -type f -name "*.extension" To find ...

Since Git 1.7.12 it is possible to rebase down to the root commit. The root commit is the first commit ever made in a repository, and normally cannot be edited. Use the following command: git rebase -i --root

Note that you cannot overload a function based on its return type. For example: // WRONG CODE std::string getValue() { return "hello"; } int getValue() { return 0; } int x = getValue(); This will cause a compilation error as the compiler will not be able to work out wh...

Filters can either be defined in a method and then added to Jinja's filters dictionary, or defined in a method decorated with Flask.template_filter. Defining and registering later: def format_datetime(value, format="%d %b %Y %I:%M %p"): """Format a date time to (Defau...

Intents can be used to broadcast messages to other components of your application (such as a running background service) or to the entire Android system. To send a broadcast within your application, use the LocalBroadcastManager class: Intent intent = new Intent("com.example.YOUR_ACTION"...

This code selects data out of a table and displays it in the query tool (usually SSMS) SELECT Column1, Column2, Column3 FROM MySourceTable; This code inserts that data into a table: INSERT INTO MyTargetTable (Column1, Column2, Column3) SELECT Column1, Column2, Column3 FROM MySourceTable;

This code selects data out of a table: SELECT Column1, Column2, Column3 FROM MySourceTable; This code creates a new table called MyNewTable and puts that data into it SELECT Column1, Column2, Column3 INTO MyNewTable FROM MySourceTable;

To move data you first insert it into the target, then delete whatever you inserted from the source table. This is not a normal SQL operation but it may be enlightening What did you insert? Normally in databases you need to have one or more columns that you can use to uniquely identify rows so we w...

Example is the main part of Documentation, it is thus important to provide clear and useful examples. Good examples are self-contained and succinct. Examples usually would have code for users to understand the topic better. Refer to the Help Center for more information.

You can access SharedPreferences in several ways: Get the default SharedPreferences file: import android.preference.PreferenceManager; SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); Get a specific SharedPreferences file: public static final String PREF_FILE_NAM...

You can use the CONVERT function to cast a datetime datatype to a formatted string. SELECT GETDATE() AS [Result] -- 2016-07-21 07:56:10.927 You can also use some built-in codes to convert into a specific format. Here are the options built into SQL Server: DECLARE @convert_code INT = 100 -- See ...

The display CSS property is fundamental for controlling the layout and flow of an HTML document. Most elements have a default display value of either block or inline (though some elements have other default values). Inline An inline element occupies only as much width as necessary. It stacks horiz...

A Sub is a procedure that performs a specific task but does not return a specific value. Sub ProcedureName ([argument_list]) [statements] End Sub If no access modifier is specified, a procedure is Public by default. A Function is a procedure that is given data and returns a value, ideally...

A class designed to be inherited-from is called a Base class. Care should be taken with the special member functions of such a class. A class designed to be used polymorphically at run-time (through a pointer to the base class) should declare the destructor virtual. This allows the derived parts of...