Tutorial by Examples: le

Sometimes a new Java programmer will write code like this: public void check(boolean ok) { if (ok == true) { // Note 'ok == true' System.out.println("It is OK"); } } An experienced programmer would spot that as being clumsy and want to rewrite it as: publ...

Pre-requisites: cx_Oracle package - See here for all versions Oracle instant client - For Windows x64, Linux x64 Setup: Install the cx_Oracle package as: sudo rpm -i <YOUR_PACKAGE_FILENAME> Extract the Oracle instant client and set environment variables as: ORACLE_HOME=&...

Adding tags to "describe" or "it" blocks allows you to run only those examples with a given tag. Use the --tag (or -t) option to run examples that match a specified tag. The tag can be a simple name or a name:value pair. If a simple name is supplied, only examples with :name...

Local variables - Those declared within a procedure (subroutine or function) of a class (or other structure). In this example, exampleLocalVariable is a local variable declared within ExampleFunction(): Public Class ExampleClass1 Public Function ExampleFunction() As Integer Dim exa...

SELECT IDENT_CURRENT('dbo.person'); This will select the most recently-added identity value on the selected table, regardless of connection or scope.

$ npm install -g parse-server mongodb-runner $ mongodb-runner start $ parse-server --appId APPLICATION_ID --masterKey MASTER_KEY --databaseURI mongodb://localhost/test You can use any arbitrary string as your application id and master key. These will be used by your clients to authenticate with...

'use strict'; const http = require('http'); const PORT = 8080; const server = http.createServer((request, response) => { let buffer = ''; request.on('data', chunk => { buffer += chunk; }); request.on('end', () => { const responseString = `Received string ${buffe...

file:write_file("myfile.txt", ["Hi " [<<"there">>], $\n]).

In greeter.rb (wherever that goes in your project): class Greeter def greet "Hello, world!" end end In spec/greeter_spec.rb: require_relative '../greeter.rb' RSpec.describe Greeter do describe '#greet' do it "says hello" do expect(Greeter.new.gr...

Clear the canvas using compositing operation. This will clear the canvas independent of transforms but is not as fast as clearRect(). ctx.globalCompositeOperation = 'copy'; anything drawn next will clear previous content.

Most Common Lisp implementations will try to load an init file on startup: ImplementationInit fileSite/System Init fileABCL$HOME/.abclrcAllegro CL$HOME/.clinit.clECL$HOME/.eclrcClasp$HOME/.clasprcCLISP$HOME/.clisprc.lispClozure CLhome:ccl-init.lisp or home:ccl-init.fasl or home:.ccl-init.lispCMUCL$...

Some programmers think that it is a good idea to save space by using a null to represent an empty array or collection. While it is true that you can save a small amount of space, the flipside is that it makes your code more complicated, and more fragile. Compare these two versions of a method for ...

All arrays implement the non-generic IList interface (and hence non-generic ICollection and IEnumerable base interfaces). More importantly, one-dimensional arrays implement the IList<> and IReadOnlyList<> generic interfaces (and their base interfaces) for the type of data that they cont...

Rust's coherence rule requires that either the trait or the type for which you are implementing the trait must be defined in the same crate as the impl, so it is not possible to implement Serialize and Deserialize for a type in a different crate directly. The newtype pattern and Deref coercion provi...

HTML: <div class="container"> <div class="child"></div> </div> CSS: .container { height: 500px; width: 500px; display: flex; // Use Flexbox align-items: center; // This centers children vertically in the parent. ...

In features/step_definitions/documentation.rb: When /^I go to the "([^"]+)" documentation$/ do |section| path_part = case section when "Documentation" "documentation" else raise "Unknown documentation section: #{section...

Let's have a look at various options to wait for completion of tasks submitted to Executor ExecutorService invokeAll() Executes the given tasks, returning a list of Futures holding their status and results when everything is completed. Example: import java.util.concurrent.*; import ja...

get_defined_vars() returns an array with all the names and values of the variables defined in the scope in which the function is called. If you want to print data you can use standard functions for outputting human-readable data, like print_r or var_dump. var_dump(get_defined_vars()); Note: This...

The simple and most obvious way to use recursion to get the Nth term of the Fibonnaci sequence is this int get_term_fib(int n) { if (n == 0) return 0; if (n == 1) return 1; return get_term_fib(n - 1) + get_term_fib(n - 2); } However, this algorithm does not scale for higher ...

Most Rails developers start by modifying their model information within the template itself: <h1><%= "#{ @user.first_name } #{ @user.last_name }" %></h1> <h3>joined: <%= @user.created_at.in_time_zone(current_user.timezone).strftime("%A, %d %b %Y %l:%M %p&q...