Tutorial by Examples: e

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...

An object cannot occupy less than 1 byte, as then the members of an array of this type would have the same address. Thus sizeof(T)>=1 always holds. It's also true that a derived class cannot be smaller than any of its base classes. However, when the base class is empty, its size is not necessaril...

How to install the Android Debugging Bridge (ADB) to a Linux system with the terminal using your distro's repositories. Install to Ubuntu/Debian system via apt: sudo apt-get update sudo apt-get install adb Install to Fedora/CentOS system via yum: sudo yum check-update sudo yum install androi...

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...

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]/...

$ cat ip.txt address range substitution pattern sample Add Sub Mul Div Lines matching a pattern $ sed '/add/d' ip.txt range substitution pattern sample Add Sub Mul Div $ sed -n '/t/p' ip.txt substitution pattern $ sed -n '/[A-Z]/ s| |/|gp' ip.txt Add/Sub/Mul/Div ...

$ cat ip.txt address range substitution pattern sample Add Sub Mul Div Line number to line matching pattern $ sed -n '2,/pat/p' ip.txt range substitution pattern Line matching pattern to line number $ sed '/pat/,$d' ip.txt address range substitution GNU sed ...

Suppose we have a file cat -n lorem_ipsum.txt 1 Lorem Ipsum is simply dummy text of the printing and typesetting industry. 2 Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen...

Follow this steps for adding splash screen into WPF application in Visual Studio: Create or get any image and add it to your project (e.g. inside Images folder): Open properties window for this image (View → Properties Window) and change Build Action setting to SplashScreen value: R...

If your application is lightweight and simple, it will launch very fast, and with similar speed will appear and disappear splash screen. As soon as splash screen disappearing after Application.Startup method completed, you can simulate application launch delay by following this steps: Open App.x...

AWK often used for manipulating entire files containing a list of strings. Let's say file awk_test_file.txt contains: First String Second String Third String To convert all the strings to lower case execute: awk '{ print tolower($0) }' awk_test_file.txt This will result: first string se...

General overview The background-size property enables one to control the scaling of the background-image. It takes up to two values, which determine the scale/size of the resulting image in vertical and and horizontal direction. If the property is missing, its deemed auto in both width and height....

Using The Terminal The examples in this document assume that you are using a POSIX-compliant (such as bash, sh, zsh, ksh) shell. Large portions of GNU/Linux functionality are achieved using the terminal. Most distributions of Linux include terminal emulators that allow users to interact with a...

# This comment occupies a whole line - some item # This comment succeeds content of a line - http://example.com/#nocomment - "This # does not introduce a comment." - | This is a block scalar. A # inside it does not introduce a comment. # unless it is less indented than th...