Tutorial by Examples: u

Analog to get a collection for a Stream by collect() an array can be obtained by the Stream.toArray() method: List<String> fruits = Arrays.asList("apple", "banana", "pear", "kiwi", "orange"); String[] filteredFruits = fruits.stream() ....

A common pitfall of child classes is that, if your parent and child both contain a constructor(__construct()) method, only the child class constructor will run. There may be occasions where you need to run the parent __construct() method from it's child. If you need to do that, then you will need to...

Instructions on installing Laravel 5.1 on a Linux/Mac/Unix Machine. Before initiating the installation, check if the following requirements are met: PHP >= 5.5.9 OpenSSL PHP Extension PDO PHP Extension Mbstring PHP Extension Tokenizer PHP Extension Let's begin the installation: Inst...

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...

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...

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...

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

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...

You can count the number of rows: SELECT count(*) TotalRows FROM employees; TotalRows4 Or count the employees per department: SELECT DepartmentId, count(*) NumEmployees FROM employees GROUP BY DepartmentId; DepartmentIdNumEmployees1321 You can count over a column/expression with the eff...

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 ...

Messages printed from NSLog are displayed on Console.app even in the release build of your app, which doesn't make sense for printouts that are only useful for debugging. To fix this, you can use this macro for debug logging instead of NSLog. #ifdef DEBUG #define DLog(...) NSLog(__VA_ARGS__) #els...

First, import the libraries that work with files: from os import listdir from os.path import isfile, join, exists A helper function to read only files from a directory: def get_files(path): for file in listdir(path): full_path = join(path, file) if isfile(full_path): ...

Syntax: add_months(p_date, integer) return date; Add_months function adds amt months to p_date date. SELECT add_months(date'2015-01-12', 2) m FROM dual; M2015-03-12 You can also substract months using a negative amt SELECT add_months(date'2015-01-12', -2) m FROM dual; M2014-11-12 When the...

public static class ThreadLocalExample { private static final ThreadLocal<SimpleDateFormat> format = ThreadLocal.withInitial(() -> new SimpleDateFormat("yyyyMMdd_HHmm")); public String formatDate(Date date) { return format.get().format(date); ...

Java ThreadLocal is used to create thread local variables. It is known that threads of an Object share it’s variables, so the variable is not thread safe. We can use synchronization for thread safety but if we want to avoid synchronization,ThreadLocal allows us to create variables which are local to...

PHP has great official documentation already at http://php.net/manual/. The PHP Manual documents pretty much all language features, the core libraries and most available extensions. There are plenty of examples to learn from. The PHP Manual is available in multiple languages and formats. Best of al...

// *** Case Insensitive comparison with matching subset *** NSPredicate *filterByName = [NSPredicate predicateWithFormat:@"self.title CONTAINS[cd] %@",@"Tom"]; NSLog(@"Filter By Containing Name : %@",[array filteredArrayUsingPredicate:filterByName]);

An enumeration is a user-defined data type consists of integral constants and each integral constant is given a name. Keyword enum is used to define enumerated data type. If you use enum instead of int or string/ char*, you increase compile-time checking and avoid errors from passing in invalid con...