Tutorial by Examples: s

INSERT INTO Customers (FName, LName, PhoneNumber) SELECT FName, LName, PhoneNumber FROM Employees This example will insert all Employees into the Customers table. Since the two tables have different fields and you don't want to move all the fields over, you need to set which fields to insert int...

Single-line comments in Lua start with -- and continue until the end of line: -- this is single line comment -- need another line -- huh? Block comments start with --[[ and end with ]]: --[[ This is block comment. So, it can go on... and on... and on.... ]] Block comme...

The "default" for constructors is that they do not have any arguments. In case you do not specify any constructor, the compiler will generate a default constructor for you. This means the following two snippets are semantically equivalent: public class TestClass { private String tes...

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...

The Lua standard library provides a pairs function which iterates over the keys and values of a table. When iterating with pairs there is no specified order for traversal, even if the keys of the table are numeric. for key, value in pairs(input_table) do print(key, " -- ", value) en...

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 /...

The first two arguments to format are an output stream and a control string. Basic use does not require additional arguments. Passing t as the stream writes to *standard-output*. > (format t "Basic Message") Basic Message nil That expression will write Basic Message to standard ou...

By default, containers created with docker run are given a random name like small_roentgen or modest_dubinsky. These names aren't particularly helpful in identifying the purpose of a container. It is possible to supply a name for the container by passing the --name command line option: docker run -...

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...