Tutorial by Examples: me

A useful feature of namespaces is that you can expand them (add members to it). namespace Foo { void bar() {} } //some other stuff namespace Foo { void bar2() {} }

Sometimes you may encounter members that have really long member names, such as thisIsWayTooLongOfAName(). In this case, you can import the member and give it a shorter name to use in your current module: import {thisIsWayTooLongOfAName as shortName} from 'module' shortName() You can import m...

Let's say you've got a list of restaurants -- maybe you read it from a file. You care about the unique restaurants in the list. The best way to get the unique elements from a list is to turn it into a set: restaurants = ["McDonald's", "Burger King", "McDonald's", &qu...

The term "IFrame" means Inline Frame. It can be used to include another page in your page. This will yield a small frame which shows the exact contents of the base.html. <iframe src="base.html"></iframe>

The IFrame can be resized using the width and height attributes, where the values are represented in pixels (HTML 4.01 allowed percentage values, but HTML 5 only allows values in CSS pixels). <iframe src="base.html" width="800" height="600"></iframe>

Normally a change of webpage within an Iframe is initiated from with the Iframe, for example, clicking a link inside the Ifame. However, it is possible to change an IFrame's content from outside the IFrame. You can use an anchor tag whose href attribute is set to the desired URL and whose target at...

jQuery code is often wrapped in jQuery(function($) { ... }); so that it only runs after the DOM has finished loading. <script type="text/javascript"> jQuery(function($) { // this will set the div's text to "Hello". $("#myDiv").text("Hello"...

To remove an element inside an array, e.g. the element with the index 1. $fruit = array("bananas", "apples", "peaches"); unset($fruit[1]); This will remove the apples from the list, but notice that unset does not change the indexes of the remaining elements. So $fr...

# Length of a string $ var='12345' $ echo "${#var}" 5 Note that it's the length in number of characters which is not necessarily the same as the number of bytes (like in UTF-8 where most characters are encoded in more than one byte), nor the number of glyphs/graphemes (some of which ...

One of the most common tasks is retrieving an existing element from the DOM to manipulate. Most commonly these methods are executed on document, because it is the root node, but all these methods work on any HTML element in the tree. They will only return children from the node it is executed on. R...

An element can be cloned by invoking the cloneNode method on it. If the first parameter passed to cloneNode is true, the children of the original will also be cloned. var original = document.getElementsByTagName("li")[0]; var clone = original.cloneNode(true);

Many databases allow to make the primary key value automatically increment when a new key is added. This ensures that every key is different. MySQL CREATE TABLE Employees ( Id int NOT NULL AUTO_INCREMENT, PRIMARY KEY (Id) ); PostgreSQL CREATE TABLE Employees ( Id SERIAL PRIMARY...

Appending an element at the end of a vector (by copying/moving): struct Point { double x, y; Point(double x, double y) : x(x), y(y) {} }; std::vector<Point> v; Point p(10.0, 2.0); v.push_back(p); // p is copied into the vector. C++11 Appending an element at the end of a vector ...

There are two primary ways of accessing elements in a std::vector index-based access iterators Index-based access: This can be done either with the subscript operator [], or the member function at(). Both return a reference to the element at the respective position in the std::vector (unles...

The jQuery function (usually aliased as $) can be used both to select elements and to create new elements. var myLink = $('<a href="http://stackexchange.com"></a>'); You can optionally pass a second argument with element attributes: var myLink = $('<a>', { 'href': 'h...

Assuming the page includes an HTML element like: <p class="small-paragraph"> This is a small <a href="https://en.wikipedia.org/wiki/Paragraph">paragraph</a> with a <a class="trusted" href="http://stackexchange.com">link</a>...

String html = "<!DOCTYPE html>" + "<html>" + "<head>" + "<title>Hello world!</title>" + "</head>" + "<body>" + ...

Standard Collections Java Collections framework A simple way to construct a List from individual data values is to use java.utils.Arrays method Arrays.asList: List<String> data = Arrays.asList("ab", "bc", "cd", "ab", "bc", "cd"); ...

The following is handy to have in build logs that identifies the build machine, and some parameters; simply make you main task depend on this task to print it before every build. <!-- Print Environment Info --> <target name="environment"> <!-- Get the current ti...

- (void)methodWithBlock:(returnType (^)(paramType1, paramType2, ...))name;