Tutorial by Examples: io

Windows Verify that you have the correct JDK. You can check it by opening command prompt (press windows key and write cmd). In the command prompt type javac -version, this will show the current version of JDK installed on your matching or an error* if Java is missing. If the JDK is not availabl...

Following is an implementation that demonstrates how an object can be serialized into its corresponding JSON string. class Test { private int idx; private String name; public int getIdx() { return idx; } public void setIdx(int idx) { this.idx = idx; ...

Simple: NSString *newString = @"My String"; From multiple strings: NSString *stringOne = @"Hello"; NSString *stringTwo = @"world"; NSString *newString = [NSString stringWithFormat:@"My message: %@ %@", stringOne, stringTwo]; Usi...

Concatenate strings with the + operator: s1 = "Hello" s2 = " " s3 = "World" puts s1 + s2 + s3 # => Hello World s = s1 + s2 + s3 puts s # => Hello World Or with the << operator: s = 'Hello' s << ' ' s << 'World' puts s # => ...

The double-quoted delimiter " and %Q sequence supports string interpolation using #{ruby_expression}: puts "Now is #{Time.now}" # Now is Now is 2016-07-21 12:47:45 +0200 puts %Q(Now is #{Time.now}) # Now is Now is 2016-07-21 12:47:45 +0200

By default, all the required libraries for build ASP.NET applications are included during the installation of Visual Studio. If a newer version of ASP.NET is released that was not included with Visual Studio, you can download the appropriate SDK library from Microsoft, which will include all the nec...

Some people have issues regarding error messages not being displayed if an existing value is being entered. For example I'm not allowing a user signup with an existing email. View <?php ...................... <?= $form->field($modelUser, 'email')->textInput(['class'=&gt...

In Python 2, range function returns a list while xrange creates a special xrange object, which is an immutable sequence, which unlike other built-in sequence types, doesn't support slicing and has neither index nor count methods: Python 2.x2.3 print(range(1, 10)) # Out: [1, 2, 3, 4, 5, 6, 7, 8, 9...

The Dart SDK includes everything you need to write and run Dart code: VM, libraries, analyzer, package manager, doc generator, formatter, debugger, and more. If you are doing web development, you will also need Dartium. Automated installation and updates Installing Dart on Windows Installing Da...

There are a couple different ways to protect your controller creation from minification. The first is called inline array annotation. It looks like the following: var app = angular.module('app'); app.controller('sampleController', ['$scope', '$http', function(a, b){ //logic here }]); The...

Overview Unity runs on Windows and Mac. There is also a Linux alpha version available. There are 4 different payment plans for Unity: Personal - Free (see below) Plus - $35 USD per month per seat (see below) Pro - $125 USD per month per seat - After subscribing to the Pro plan for 24 consecut...

The static (compile-time) type is used rather than the dynamic (run-time type) to match parameters. public class Base { public virtual string GetName() { return "Base"; } } public class Derived : Base { public override string GetName() { ...

What is Ubuntu Ubuntu is an open source software platform, but colloquially, when Ubuntu is referred to it's mainly toward the Ubuntu operating system. Ubuntu is based on Debian and uses the same package management system (deb and apt). Installation So you want to give Ubuntu a try! That's gr...

You may need to convert a Stream emitting Optional to a Stream of values, emitting only values from existing Optional. (ie: without null value and not dealing with Optional.empty()). Optional<String> op1 = Optional.empty(); Optional<String> op2 = Optional.of("Hello World");...

The function php_sapi_name() and the constant PHP_SAPI both return the type of interface (Server API) that is being used by PHP. They can be used to restrict the execution of a script to the command line, by checking whether the output of the function is equal to cli. if (php_sapi_name() === 'cli')...

Add/remove fields in existing tables Create a migration by running: rails generate migration AddTitleToCategories title:string This will create a migration that adds a title column to a categories table: class AddTitleToCategories < ActiveRecord::Migration[5.0] def change add_column...

preg_match checks whether a string matches the regular expression. $string = 'This is a string which contains numbers: 12345'; $isMatched = preg_match('%^[a-zA-Z]+: [0-9]+$%', $string); var_dump($isMatched); // bool(true) If you pass in a third parameter, it will be populated with the matchi...

This is the Python 2 syntax, note the commas , on the raise and except lines: Python 2.x2.3 try: raise IOError, "input/output error" except IOError, exc: print exc In Python 3, the , syntax is dropped and replaced by parenthesis and the as keyword: try: raise IOErro...

"string".upcase # => "STRING" "STRING".downcase # => "string" "String".swapcase # => "sTRING" "string".capitalize # => "String" These four methods do not modify the original receiver. For exampl...

interface IFoo { } class Foo : IFoo { } class Bar : IFoo { } var item0 = new Foo(); var item1 = new Foo(); var item2 = new Bar(); var item3 = new Bar(); var collection = new IFoo[] { item0, item1, item2, item3 }; Using OfType var foos = collection.OfType<Foo>(); // result: IEnum...