Tutorial by Examples: r

The system_clock can be used to measure the time elapsed during some part of a program's execution. c++11 #include <iostream> #include <chrono> #include <thread> int main() { auto start = std::chrono::system_clock::now(); // This and "end"'s type is std::chron...

This example shows how a function can accept pipelined input, and iterate efficiently. Note, that the begin and end structures of the function are optional when pipelining, but that process is required when using ValueFromPipeline or ValueFromPipelineByPropertyName. function Write-FromPipeline{ ...

This is an example of a function with the simplest possible support for pipelining. Any function with pipeline support must have at least one parameter with the ParameterAttribute ValueFromPipeline or ValueFromPipelineByPropertyName set, as shown below. function Write-FromPipeline { param( ...

Prevent access to your .htaccess file <Files .htaccess> order allow,deny deny from all </Files> # Rename the file AccessFileName thehtfile.ess Prevent URL attacks # Enable rewrites RewriteEngine On # Block <script> tags from executing in the URL RewriteCond %{QUE...

This is a simple example to display read-only data that is tabular in nature using Qt's Model/View Framework. Specifically, the Qt Objects QAbstractTableModel (sub-classed in this example) and QTableView are used. Implementations of the methods rowCount(), columnCount(), data() and headerData() are...

With generics, it's possible to return whatever the caller expects: private Map<String, Object> data; public <T> T get(String key) { return (T) data.get(key); } The method will compile with a warning. The code is actually more safe than it looks because the Java runtime will d...

Assuming we have a TravelReview table with City names as column "title" Criteria criteria = session.createCriteria(TravelReview.class); List review = criteria.add(Restrictions.eq("title", "Mumbai")).list(); System.out.println("Using equals: "...

Should we wish to retrieve only a few columns, we can use the Projections class to do so. For example, the following code retrieves the title column // Selecting all title columns List review = session.createCriteria(TravelReview.class) .setProjection(Projections.property("titl...

Destructuring allows you to extract data from various objects into distinct variables. In each example below, each variable is assigned to its own string (a="a", b="b", &c.) TypeExampleValue of data / commentvec(let [[a b c] data ...)["a" "b" "c&quot...

Storing Properties in a XML File The way you store properties files as XML files is very similar to the way you would store them as .properties files. Just instead of using the store() you would use storeToXML(). public void saveProperties(String location) throws IOException{ // make new inst...

In the Project.pro file we add : CONFIG += sql in MainWindow.h we write : #include <QMainWindow> #include <QSql> #include <QDebug> namespace Ui { class MainWindow; } class MainWindow : public QMainWindow { Q_OBJECT public: explicit MainWindow(QWidget...

The Common Language Runtime (CLR) is a virtual machine environment and part of the .NET Framework. It contains: A portable bytecode language called Common Intermediate Language (abbreviated CIL, or IL) A Just-In-Time compiler that generates machine code A tracing garbage collector that provides...

# provision/bootstrap-controller.sh : path and shell filename from vagrantfile location config.vm.define "configcontroller" do |controller| ... controller.vm.provision :shell do |shell| shell.path = "provision/bootstrap-controller.sh" end ...

Considering the following document : <?xml version='1.0' encoding='UTF-8' ?> <library> <book id='1'>Effective Java</book> <book id='2'>Java Concurrency In Practice</book> </library> One can use the following code to build a DOM tree out of a St...

Considering the following document : <?xml version='1.0' encoding='UTF-8' ?> <library> <book id='1'>Effective Java</book> <book id='2'>Java Concurrency In Practice</book> <notABook id='3'>This is not a book element</notABook> </librar...

Method references make excellent self-documenting code, and using method references with Streams makes complicated processes simple to read and understand. Consider the following code: public interface Ordered { default int getOrder(){ return 0; } } public interface Valued&lt...

Gradient Boosting for classification. The Gradient Boosting Classifier is an additive ensemble of a base model whose error is corrected in successive iterations (or stages) by the addition of Regression Trees which correct the residuals (the error of the previous stage). Import: from sklearn.ensem...

Starting an Ionic App $ ionic start myapp [template] Starter templates can either come from a named template, a Github repo, a Codepen, or a local directory. A starter template is what becomes the www directory within the Cordova project. Named template starters tabs (Default) sidemen...

Given a file file.txt with the following content: line 1 line 2 line 3 You can add a new line using below command sed '/line 2/{x;p;x;}' file.txt The above command will output line 1 line 2 line 3 Explanation: x command is eXchange. sed has a buffer that you can use to store some ...

$ cat ip.txt address range substitution pattern sample Range specified is inclusive of those line numbers $ sed -n '2,4p' ip.txt range substitution pattern $ can be used to specify last line. Space can be used between address and command for clarity $ sed -n '3,$ s/[aeiou]/...