Tutorial by Examples: ha

vimtutor is an interactive tutorial covering the most basic aspects of text editing. On UNIX-like system, you can start the tutorial with: $ vimtutor On Windows, “Vim tutor” can be found in the “Vim 7.x” directory under “All Programs” in the Windows menu. See :help vimtutor for further details...

Python is a hybrid interpreter. When running a program, it first assembles it into bytecode which can then be run in the Python interpreter (also called a Python virtual machine). The dis module in the standard library can be used to make the Python bytecode human-readable by disassembling classes, ...

Enum constants are instantiated when an enum is referenced for the first time. Therefore, that allows to implement Singleton software design pattern with a single-element enum. public enum Attendant { INSTANCE; private Attendant() { // perform some initialization routine ...

If you want to support a url parameter more complex than an id number, you may run into trouble with the parser if the value contains a period. Anything following a period will be assumed to be a format (i.e. json, xml). You can work around this limitation by using a constraint to broaden the accep...

JSFiddle: https://jsfiddle.net/UnsungHero97/80qod7aL/5/ HTML <div class="box_shadow"></div> CSS .box_shadow { width: 100px; height: 100px; margin: 100px; box-shadow: -52px -52px 0px 0px #f65314, 52px -52px 0px 0px #7cbb00, -52px 52px 0px 0px #00...

Given a String and a Character let text = "Hello World" let char: Character = "o" We can count the number of times the Character appears into the String using let sensitiveCount = text.characters.filter { $0 == char }.count // case-sensitive let insensitiveCount = text.low...

If you have created a table with some wrong schema, then the easiest way to change the columns and their properties is change_table. Review the following example: change_table :orders do |t| t.remove :ordered_at # removes column ordered_at t.string :skew_number # adds a new column t.index...

Managed resources are resources that the runtime's garbage collector is aware and under control of. There are many classes available in the BCL, for example, such as a SqlConnection that is a wrapper class for an unmanaged resource. These classes already implement the IDisposable interface -- it's u...

If you want to handle such scenario just add an if/else statement. if ( have_posts() ) : while ( have_posts() ) : the_post(); var_dump( $post ); endwhile; else : __('This Query does not have any results'); endif;

This design pattern is useful for generating a sequence of asynchronous actions from a list of elements. There are two variants : the "then" reduction, which builds a chain that continues as long as the chain experiences success. the "catch" reduction, which builds a chain t...

int *ptr = nullptr; *ptr = 1; // Undefined behavior This is undefined behavior, because a null pointer does not point to any valid object, so there is no object at *ptr to write to. Although this most often causes a segmentation fault, it is undefined and anything can happen.

Omitting the return statement in a function which is has a return type that is not void is undefined behavior. int function() { // Missing return statement } int main() { function(); //Undefined Behavior } Most modern day compilers emit a warning at compile time for this kind o...

Events that work with most form elements (e.g., change, keydown, keyup, keypress) do not work with contenteditable. Instead, you can listen to changes of contenteditable contents with the input event. Assuming contenteditableHtmlElement is a JS DOM object that is contenteditable: contenteditableH...

Here is an example class which has a couple of instance variables, without using properties: @interface TestClass : NSObject { NSString *_someString; int _someInt; } -(NSString *)someString; -(void)setSomeString:(NSString *)newString; -(int)someInt; -(void)setSomeInt:(NSString *)...

A has_one association sets up a one-to-one connection with another model, but with different semantics. This association indicates that each instance of a model contains or possesses one instance of another model. For example, if each user in your application has only one account, you'd declare the...

A has_many association indicates a one-to-many connection with another model. This association generally is located on the other side of a belongs_to association. This association indicates that each instance of the model has zero or more instances of another model. For example, in an application ...

Alamofire.request(.GET, "https://httpbin.org/get", parameters: ["foo": "bar"]) .responseJSON { response in print(response.request) // original URL request print(response.response) // URL response print(response.data) // server da...

Alamofire.request(.GET, "https://httpbin.org/get", parameters: ["foo": "bar"]) .validate() .response { request, response, data, error in print(request) print(response) print(data) print(error) }

Alamofire.request(.GET, "https://httpbin.org/get") .validate() .responseString { response in print("Response String: \(response.result.value)") } .responseJSON { response in print("Response JSON: \(response.result.value)") ...

public string Remove() { string input = "Hello./!"; return Regex.Replace(input, "[^a-zA-Z0-9]", ""); }