Tutorial by Examples: s

Detailed instructions on getting model-view-controller set up or installed.

Redirect any naked domain to www.[your_domain].tld: # Start Apache Rewriting engine RewriteEngine On # Make sure you're not already using www subdomain # and that the host string is not empty RewriteCond %{HTTP_HOST} !^$ RewriteCond %{HTTP_HOST} !^www\. # We check for http/https connection ...

insert :: Ord a => a -> [a] -> [a] insert x [] = [x] insert x (y:ys) | x < y = x:y:ys | otherwise = y:(insert x ys) isort :: Ord a => [a] -> [a] isort [] = [] isort (x:xs) = insert x (isort xs) Example use: > isort [5,4,3,2,1] Result: [1,2,3,4...

Ordered merging of two ordered lists Preserving the duplicates: merge :: Ord a => [a] -> [a] -> [a] merge xs [] = xs merge [] ys = ys merge (x:xs) (y:ys) | x <= y = x:merge xs (y:ys) | otherwise = y:merge (x:xs) ys Top-down version: msort :: Ord a => [...

qsort :: (Ord a) => [a] -> [a] qsort [] = [] qsort (x:xs) = qsort [a | a <- xs, a < x] ++ [x] ++ qsort [b | b <- xs, b >= x]

XML pre-defines five general entities that can be used without declaring them: & " ' < > They are associated with the names amp, quot, apos, lt and gt. <?xml version="1.0"?> <entities> & is an ampersand. " is a quote. ' is...

It is possible to define one's own general entities. The declaration occurs in the DTD subset, with a name and the associated replacement text. It can then be used in the document using the entity reference syntax &...;, either in text, or in attribute values. <?xml version="1.0"?...

Show the changes between the tip of new and the tip of original: git diff original new # equivalent to original..new Show all changes on new since it branched from original: git diff original...new # equivalent to $(git merge-base original new)..new Using only one parameter such as ...

This is the most basic version of a trait in Scala. trait Identifiable { def getIdentifier: String def printIndentification(): Unit = println(getIdentifier) } case class Puppy(id: String, name: String) extends Identifiable { def getIdentifier: String = s"$name has id $id" } ...

The HasFlag() method can be used to check if a flag is set. Module Module1 <Flags> Enum Material Wood = 1 Plastic = 2 Metal = 4 Stone = 8 End Enum Sub Main() Dim houseMaterials As Material = Material.Wood Or Material.Stone ...

${parameter:-word} If parameter is unset or null, the expansion of word is substituted. Otherwise, the value of parameter is substituted. $ unset var $ echo "${var:-XX}" # Parameter is unset -> expansion XX occurs XX $ var="" # Parameter is null ...

The semantics for this are similar to that of default value substitution, but instead of substituting a default value, it errors out with the provided error message. The forms are ${VARNAME?ERRMSG} and ${VARNAME:?ERRMSG}. The form with : will error our if the variable is unset or empty, whereas the ...

To create a JAR containing all of its dependencies, it is possible to use the built-in descriptor format jar-with-dependencies. The following example configures an execution of the Assembly Plugin bound to the package phase, using this built-in descriptor and declaring a main class of com.example: ...

Shortest match: $ a='I am a string' $ echo "${a#*a}" m a string Longest match: $ echo "${a##*a}" string

Shortest match: $ a='I am a string' $ echo "${a%a*}" I am Longest match: $ echo "${a%%a*}" I

First match: $ a='I am a string' $ echo "${a/a/A}" I Am a string All matches: $ echo "${a//a/A}" I Am A string Match at the beginning: $ echo "${a/#I/y}" y am a string Match at the end: $ echo "${a/%g/N}" I am a strinN Replace a pattern wi...

Project Object Model is the basic unit of Maven and defines the project structure, dependencies, etc. The following are very minimal to create a POM: project root modelVersion – should be set to 4.0.0 groupId – the ID of the project's group artifactId – the ID of the artifact (project) versi...

In [15]: df = pd.DataFrame({"A":[1,1,2,3,1,1],"B":[5,4,3,4,6,7]}) In [21]: df Out[21]: A B 0 1 5 1 1 4 2 2 3 3 3 4 4 1 6 5 1 7 To get unique values in column A and B. In [22]: df["A"].unique() Out[22]: array([1, 2, 3]) In [23]: df[&qu...

An erlang module is a file with couple of functions grouped together. This file usually has .erl extension. A "Hello World" module with name hello.erl is shown below -module(hello). -export([hello_world/0]). hello_world() -> io:format("Hello, World!~n", []). In the...

You can take advantage of Apache Maven's powerful features in Eclipse by installing the M2Eclipse feature. Follow these steps to install Maven in Eclipse: Open Eclipse and select Help → Install New Software… In the opened dialog, select the Add... button to add a new repository. Fill ...