Tutorial by Examples: re

This example shows how to create a prepared statement with an insert statement with parameters, set values to those parameters and then executing the statement. Connection connection = ... // connection created earlier try (PreparedStatement insert = connection.prepareStatement( "i...

To connect to MySQL you need to use the MySQL Connector/J driver. You can download it from http://dev.mysql.com/downloads/connector/j/ or you can use Maven: <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version...

When you create a function in TypeScript you can specify the data type of the function's arguments and the data type for the return value Example: function sum(x: number, y: number): number { return x + y; } Here the syntax x: number, y: number means that the function can accept two argum...

Example: function hello(name: string): string { return `Hello ${name}!`; } Here the syntax name: string means that the function can accept one name argument and this argument can only be string and (...): string { means that the return value can only be a string Usage: hello('StackOverfl...

Dart has a robust async library, with Future, Stream, and more. However, sometimes you might run into an asynchronous API that uses callbacks instead of Futures. To bridge the gap between callbacks and Futures, Dart offers the Completer class. You can use a Completer to convert a callback into a Fut...

If you want to access a workbook that's already open, then getting the assignment from the Workbooks collection is straightforward: dim myWB as Workbook Set myWB = Workbooks("UsuallyFullPathnameOfWorkbook.xlsx") If you want to create a new workbook, then use the Workbooks collection o...

To create a project called helloworld run: stack new helloworld simple This will create a directory called helloworld with the files necessary for a Stack project.

File structure A simple project has the following files included in it: ➜ helloworld ls LICENSE Setup.hs helloworld.cabal src stack.yaml In the folder src there is a file named Main.hs. This is the "starting point" of the helloworld project. By default...

Stackage is a repository for Haskell packages. We can add these packages to a stack project. Adding lens to a project. In a stack project, there is a file called stack.yaml. In stack.yaml there is a segment that looks like: resolver: lts-6.8 Stackage keeps a list of packages for every revision...

Example uses of $(document).ready(): Attaching event handlers Attach jQuery event handlers $(document).ready(function() { $("button").click(function() { // Code for the click function }); }); Run jQuery code after the page structure is created jQuery(function($) ...

This program copies a file using readable and a writable stream with the pipe() function provided by the stream class // require the file system module var fs = require('fs'); /* Create readable stream to file in current directory named 'node.txt' Use utf8 encoding Read the data...

I/O in node is asynchronous, so interacting with the disk and network involves passing callbacks to functions. You might be tempted to write code that serves up a file from disk like this: var http = require('http'); var fs = require('fs'); var server = http.createServer(function (req, res) { ...

app.js const readline = require('readline'); const fs = require('fs'); var file = 'path.to.file'; var rl = readline.createInterface({ input: fs.createReadStream(file), output: process.stdout, terminal: false }); rl.on('line', function (line) { console.log(line) // print...

Hstore columns can be useful to store settings. They are available in PostgreSQL databases after you enabled the extension. class CreatePages < ActiveRecord::Migration[5.0] def change create_table :pages do |t| enable_extension 'hstore' unless extension_enabled?('hstore') t...

Download and install Xamarin Studio Community. Open Xamarin Studio. Click File → New → Solution. Click .NET → Console Project and choose C#. Click Next to proceed. Enter the Project Name and Browse... for a Location to Save and then click Create. The newly created project w...

Creating the JFrame Creating a window is easy. You just have to create a JFrame. JFrame frame = new JFrame(); Titling the Window You may wish to give your window a title. You can so do by passing a string when creating the JFrame, or by calling frame.setTitle(String title). JFrame frame = new...

The following examples show 3 main methods for installing Erlang/OTP on FreeBSD. Method 1 - Pre-built Binary Package Use pkg to install the pre-built binary package: $ pkg install erlang Test your new installation: $ erl Erlang/OTP 18 [erts-7.3.1] [source] [64-bit] [smp:2:2] [async-threads:1...

You can build a JSON object tree (a JsValue) manually import play.api.libs.json._ val json = JsObject(Map( "name" -> JsString("Jsony McJsonface"), "age" -> JsNumber(18), "hobbies" -> JsArray(Seq( JsString("Fishing"), ...

Catamorphisms, or folds, model primitive recursion. cata tears down a fixpoint layer by layer, using an algebra function (or folding function) to process each layer. cata requires a Functor instance for the template type f. cata :: Functor f => (f a -> a) -> Fix f -> a cata f = f . fma...

Anamorphisms, or unfolds, model primitive corecursion. ana builds up a fixpoint layer by layer, using a coalgebra function (or unfolding function) to produce each new layer. ana requires a Functor instance for the template type f. ana :: Functor f => (a -> f a) -> a -> Fix f ana f = Fi...