Tutorial by Examples: a

To support a given application, you often create a new role and database to match. The shell commands to run would be these: $ createuser -P blogger Enter password for the new role: ******** Enter it again: ******** $ createdb -O blogger blogger This assumes that pg_hba.conf has been prope...

Table file with header, footer, row names, and index column: file: table.txt This is a header that discusses the table file to show space in a generic table file index name occupation 1 Alice Salesman 2 Bob Engineer 3 Charlie Janitor This is a footer becaus...

Introduction The BufferedReader class is a wrapper for other Reader classes that serves two main purposes: A BufferedReader provides buffering for the wrapped Reader. This allows an application to read characters one at a time without undue I/O overheads. A BufferedReader provides functi...

If we know the length of the string, we can use a for loop to iterate over its characters: char * string = "hello world"; /* This 11 chars long, excluding the 0-terminator. */ size_t i = 0; for (; i < 11; i++) { printf("%c\n", string[i]); /* Print each character of ...

In C, a string is a sequence of characters that is terminated by a null character ('\0'). We can create strings using string literals, which are sequences of characters surrounded by double quotation marks; for example, take the string literal "hello world". String literals are automatica...

An array of strings can mean a couple of things: An array whose elements are char *s An array whose elements are arrays of chars We can create an array of character pointers like so: char * string_array[] = { "foo", "bar", "baz" }; Remember: w...

A minimal CMake project file that uses Qt5 can be: cmake_minimum_required(VERSION 2.8.11) project(myproject) find_package(Qt5 5.7.0 REQUIRED COMPONENTS Core ) set(CMAKE_AUTOMOC ON) add_executable(${PROJECT_NAME} main.cpp ) target_link_libraries(${PROJECT_NAME} Qt5::C...

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(QWid...

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...

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...

Layout Unity basic editor will look like below. Basic functionalities of some default windows/tabs are described in the image. Linux Layout There is a little difference in menu layout of linux version, like the screenshot below, Basic Usage Create an empty GameObject by right clicking in th...

Using the default constructor T variable = Activator.CreateInstance(typeof(T)); Using parameterized constructor T variable = Activator.CreateInstance(typeof(T), arg1, arg2);

Occasionally you'd want to catch an exception and throw it from a different thread or method while preserving the original exception stack. This can be done with ExceptionDispatchInfo: using System.Runtime.ExceptionServices; void Main() { ExceptionDispatchInfo capturedException = null; ...

Due to logical query processing order, alias can be used in order by. SELECT DisplayName, JoinDate as jd, Reputation as rep FROM Users ORDER BY jd, rep And can use relative order of the columns in the select statement .Consider the same example as above and instead of using alias use the relat...

Whenever a Python script is invoked from the command line, the user may supply additional command line arguments which will be passed on to the script. These arguments will be available to the programmer from the system variable sys.argv ("argv" is a traditional name used in most programmi...

To install Eclipse RCP follow the steps : Download Eclipse RCP/RAP version from Eclipse.org Eclipse RCP/RAP project downloading URL

The @Html.AntiForgeryToken() helper method protects against cross-site request forgery (or CSRF) attacks. It can be used by simply using the Html.AntiForgeryToken() helper within one of your existing forms and decorating its corresponding Controller Action with the [ValidateAntiForgeryToken] attri...

Good unit tests are independent, but code often has dependencies. We use various kinds of test doubles to remove the dependencies for testing. One of the simplest test doubles is a stub. This is a function with a hard-coded return value called in place of the real-world dependency. // Test that ...

If you are able to download an update of Android Studio, but after it restarts nothing happens, check out the following example: After the patch was downloaded and Android Studio closed, open the terminal Go to your android studio folder, e.g. cd ~/android-studio Go to bin subfolder: cd bin ...

.NET Framework defines a interface for types requiring a tear-down method: public interface IDisposable { void Dispose(); } Dispose() is primarily used for cleaning up resources, like unmanaged references. However, it can also be useful to force the disposing of other resources even though ...