Tutorial by Examples: re

Consider the utility class pattern: a class with only static methods and no fields. It's recommended to prevent instantiation of such classes by adding a private a constructor. This live template example makes it easy to add a private constructor to an existing class, using the name of the enclos...

main.go: package main import ( "fmt" "io/ioutil" "log" "net/http" ) func fetchContent(url string) (string, error) { res, err := http.Get(url) if err != nil { return "", nil } defer res.Body.Clo...

Maps and keyword lists have different application. For instance, a map cannot have two keys with the same value and it's not ordered. Conversely, a Keyword list can be a little bit hard to use in pattern matching in some cases. Here's a few use cases for maps vs keyword lists. Use keyword lists wh...

C++11 In C++11, compilers are required to implicitly move from a local variable that is being returned. Moreover, most compilers can perform copy elision in many cases and elide the move altogether. As a result of this, returning large objects that can be moved cheaply no longer requires special ha...

create-react-app is a React app boilerplate generator created by Facebook. It provides a development environment configured for ease-of-use with minimal setup, including: ES6 and JSX transpilation Dev server with hot module reloading Code linting CSS auto-prefixing Build script with JS, CSS ...

One problem often seen in code is loading all the data. This will greatly increase the load on the server. Let's say I have a model called "location" that has 10 fields in it, but not all the fields are required at the same time. Let's say I only want the 'LocationName' parameter of that...

repeat(10) { i -> println("This line will be printed 10 times") println("We are on the ${i + 1}. loop iteration") }

Break and continue keywords work like they do in other languages. while(true) { if(condition1) { continue // Will immediately start the next iteration, without executing the rest of the loop body } if(condition2) { break // Will exit the loop completely } } ...

We got the following very basic element my-element saved as src/my-element.html <link rel="import" href="bower_components/polymer/polymer.html"> <dom-module id="my-element"> <template> <style> /* local styles go here */ ...

Occasionally, we may want to display dialogs with more than one pane of content. jQuery UI offers tabs that can be used in tandem with a dialog to make this possible. While it may be more common to have tabs within a dialog's content container, this example will demonstrate how to make a list of t...

Higher-order functions can be used to ensure that system resources are disposed, even when a treatment raises an exception. The pattern used by with_output_file allows a clean separation of concerns: the higher-order with_output_file functions takes care of managing the system resources bound to fi...

The ls command has several options that can be used together to show more information. Details/Rights The l option shows the file permissions, size, and last modified date. So if the root directory contained a dir called test and a file someFile the command: user@linux-computer:~$ ls -l Would ...

A deadlock occurs when two competing actions wait for the other to finish, and thus neither ever does. In java there is one lock associated with each object. To avoid concurrent modification done by multiple threads on single object we can use synchronized keyword, but everything comes at a cost....

Once you have Sails installed, just type $ sails new <project_name> This will create a skeleton Sails project in a new folder called <project_name>. You can also create a new project in an empty folder by typing $ sails new

A list of references to members of a group, such as a static table of contents. <ul role="directory"> <li><a href="/chapter-1">Chapter 1</a></li> <li><a href="/chapter-2">Chapter 2</a></li> <li><a ...

An element whose implicit native role semantics will not be mapped to the accessibility API. <div style="float:left;">Some content on the left.</div> <div style="float:right;">Some content on the right</div> <div role="presentation" style=&...

An element that displays the progress status for tasks that take a long time. <progress role="progressbar" value="25" max="100">25%</progress>

A large perceivable section of a web page or document, that the author feels is important enough to be included in a page summary or table of contents, for example, an area of the page containing live sporting event statistics. <div role="region"> Home team: 4<br> Away t...

A type of list that may contain sub-level nested groups that can be collapsed and expanded. <ul role="tree"> <li role="treeitem"> Part 1 <ul> <li role="treeitem">Chapter 1</li> <li role="treeitem"&gt...

A grid whose rows can be expanded and collapsed in the same manner as for a tree.