Tutorial by Examples: o

Constructors can be created with any kinds of arguments. public class TestClass { private String testData; public TestClass(String testData) { this.testData = testData; } } Called like this: TestClass testClass = new TestClass("Test Data"); A class can ...

Each individual CSS Selector has its own specificity value. Every selector in a sequence increases the sequence's overall specificity. Selectors fall into one of three different specificity groups: A, B and c. When multiple selector sequences select a given element, the browser uses the styles appli...

Node.js package configurations are contained in a file called package.json that you can find at the root of each project. You can setup a brand new configuration file by calling: npm init That will try to read the current working directory for Git repository information (if it exists) and enviro...

HTML input validation is done automatically by the browser based on special attributes on the input element. It could partially or completely replace JavaScript input validation. This kind of validation can be circumvented by the user via specially crafted HTTP requests, so it does not replace serve...

Usually, Lua is being shipped with two binaries: lua - standalone interpreter and interactive shell luac - bytecode compiler Lets say we have an example program (bottles_of_mate.lua) like this: local string = require "string" function bottle_take(bottles_available) lo...

Reflection is often used as part of software testing, such as for the runtime creation/instantiation of mock objects. It's also great for inspecting the state of an object at any given point in time. Here's an example of using Reflection in a unit test to verify a protected class member contains the...

Supposing the following list we can sort a variety of ways. val names = List("Kathryn", "Allie", "Beth", "Serin", "Alana") The default behavior of sorted() is to use math.Ordering, which for strings results in a lexographic sort: names.sorted /...

docker run -p "8080:8080" myApp docker run -p "192.168.1.12:80:80" nginx docker run -P myApp In order to use ports on the host have been exposed in an image (via the EXPOSE Dockerfile directive, or --expose command line option for docker run), those ports need to be bound to...

main = do input <- getContents putStr input Input: This is an example sentence. And this one is, too! Output: This is an example sentence. And this one is, too! Note: This program will actually print parts of the output before all of the input has been fully read in. This m...

main = do line <- getLine putStrLn line Input: This is an example. Output: This is an example.

readFloat :: IO Float readFloat = fmap read getLine main :: IO () main = do putStr "Type the first number: " first <- readFloat putStr "Type the second number: " second <- readFloat putStrLn $ show first ++ " + " ++ show se...

Like in several other parts of the I/O library, functions that implicitly use a standard stream have a counterpart in System.IO that performs the same job, but with an extra parameter at the left, of type Handle, that represents the stream being handled. For instance, getLine :: IO String has a cou...

A bit counter-intuitive to the way most other languages' standard I/O libraries do it, Haskell's isEOF does not require you to perform a read operation before checking for an EOF condition; the runtime will do it for you. import System.IO( isEOF ) eofTest :: Int -> IO () eofTest line = do ...

During a merge, you can pass --ours or --theirs to git checkout to take all changes for a file from one side or the other of a merge. $ git checkout --ours -- file1.txt # Use our version of file1, delete all their changes $ git checkout --theirs -- file2.txt # Use their version of file2, delete ...

$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 2bc9b1988080 redis "docker-entrypoint.sh" 2 weeks ago Up 2 hours 0.0.0.0:6379->6379/tcp eleph...

Docker commands which take the name of a container accept three different forms: TypeExampleFull UUID9cc69f11a0f76073e87f25cb6eaf0e079fbfbd1bc47c063bcd25ed3722a8cc4aShort UUID9cc69f11a0f7Nameberserk_wozniak Use docker ps to view these values for the containers on your system. The UUID is generat...

To stop a running container: docker stop <container> [<container>...] This will send the main process in the container a SIGTERM, followed by a SIGKILL if it doesn't stop within the grace period. The name of each container is printed as it stops. To start a container which is stoppe...

Ordinarily, images are pulled automatically from Docker Hub. Docker will attempt to pull any image from Docker Hub that doesn't already exist on the Docker host. For example, using docker run ubuntu when the ubuntu image is not already on the Docker host will cause Docker to initiate a pull of the l...

$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest 693bce725149 6 days ago 967 B postgres 9.5 0f3af79d8673 10 weeks ago 265.7 MB postgres ...

Once you've paused execution on a breakpoint, you may want to follow execution line-by-line to observe what happens. Open your browser's Developer Tools and look for the Execution Control icons. (This example uses the icons in Google Chrome, but they'll be similar in other browsers.) Resume: Unpau...