Tutorial by Examples: ha

INotifyPropertyChanged is an interface used by binding sources (i.e. the DataContext) to let the user interface or other components know that a property has been changed. WPF automatically updates the UI for you when it sees the PropertyChanged event raised. It is desirable to have this interface im...

Class implementation: CLASS lcl_abap_class DEFINITION. PRIVATE SECTION. METHODS method1 IMPORTING iv_string TYPE string CHANGING cv_string TYPE string EXPORTING ev_string TYPE string. ENDCLASS. CLASS lcl_abap_class IMPLEMENTATION. METHOD m...

Type type = obj.GetType(); //To restrict return properties. If all properties are required don't provide flag. BindingFlags flags = BindingFlags.Public | BindingFlags.Instance; PropertyInfo[] properties = type.GetProperties(flags); foreach (PropertyInfo property in properties) { Console...

To document a function, it is often helpful to have an example script which uses your function. The publish function in Matlab can then be used to generate a help file with embedded pictures, code, links, etc. The syntax for documenting your code can be found here. The Function This function uses ...

Folds are (higher-order) functions used with sequences of elements. They collapse seq<'a> into 'b where 'b is any type (possibly still 'a). This is a bit abstract so lets get into concrete practical examples. Calculating the sum of all numbers In this example, 'a is an int. We have a list of...

In a non-strict-mode scope, when a variable is assigned without being initialized with the var, const or the let keyword, it is automatically declared in the global scope: a = 12; console.log(a); // 12 In strict mode however, any access to an undeclared variable will throw a reference error: &...

If you have a string that contains Python literals, such as strings, floats etc, you can use ast.literal_eval to evaluate its value instead of eval. This has the added feature of allowing only certain syntax. >>> import ast >>> code = """(1, 2, {'foo': 'bar'})&quot...

With ASP.NET Core 1.0, the MVC and Web API framework have been merged into one framework called ASP.NET Core MVC. This is a good thing, since MVC and Web API share a lot of functionality, yet there always were subtle differences and code duplication. However, merging these two into framework one ...

Our example array: arr=(a b c d e f) Using a for..in loop: for i in "${arr[@]}"; do echo "$i" done 2.04 Using C-style for loop: for ((i=0;i<${#arr[@]};i++)); do echo "${arr[$i]}" done Using while loop: i=0 while [ $i -lt ${#arr[@]} ]; do...

Angular 2.0.0-rc.4 In this example we'll create a "Hello World!" app with only one root component (AppComponent) for the sake of simplicity. Prerequisites: Node.js v5 or later npm v3 or later Note: You can check versions by running node -v and npm -v in the console/terminal. ...

For each environment you need to create a separate appsettings.{EnvironmentName}.json files: appsettings.Development.json appsettings.Staging.json appsettings.Production.json Then open project.json file and include them into "include" in "publishOptions" section. This lis...

The $_FILES["FILE_NAME"]['error'] (where "FILE_NAME" is the value of the name attribute of the file input, present in your form) might contain one of the following values: UPLOAD_ERR_OK - There is no error, the file uploaded with success. UPLOAD_ERR_INI_SIZE - The uploaded fi...

The HasFlag() method can be used to check if a flag is set. Module Module1 <Flags> Enum Material Wood = 1 Plastic = 2 Metal = 4 Stone = 8 End Enum Sub Main() Dim houseMaterials As Material = Material.Wood Or Material.Stone ...

To create a JAR containing all of its dependencies, it is possible to use the built-in descriptor format jar-with-dependencies. The following example configures an execution of the Assembly Plugin bound to the package phase, using this built-in descriptor and declaring a main class of com.example: ...

functions.php: // We add the action twice, once for logged in users and once for non logged in users. add_action( 'wp_ajax_my_action', 'my_action_callback' ); add_action( 'wp_ajax_nopriv_my_action', 'my_action_callback' ); // Enqueue the script on the front end. add_action( 'wp_enqueue_script...

Attach an Event Handler Since version 1.7 jQuery has the event API .on(). This way any standard javascript event or custom event can be bound on the currently selected jQuery element. There are shortcuts such as .click(), but .on() gives you more options. HTML <button id="foo">b...

For the character entity character(len=5), parameter :: greeting = "Hello" a substring may be referenced with the syntax greeting(2:4) ! "ell" To access a single letter it isn't sufficient to write greeting(1) ! This isn't the letter "H" but greeting(1:...

There may be situations where you have setup a pool of MySQL connections, but you have a number of queries you would like to run in sequence: SELECT 1; SELECT 2; You could just run then using pool.query as seen elsewhere, however if you only have one free connection in the pool you must wait un...

This is a collection of unique items, with O(1) lookup. HashSet<int> validStoryPointValues = new HashSet<int>() { 1, 2, 3, 5, 8, 13, 21 }; bool containsEight = validStoryPointValues.Contains(8); // O(1) By way of comparison, doing a Contains on a List yields poorer performance: Lis...

TCO is only available in strict mode As always check browser and Javascript implementations for support of any language features, and as with any javascript feature or syntax, it may change in the future. It provides a way to optimise recursive and deeply nested function calls by eliminating the n...