Tutorial by Examples: r

with Ada.Text_IO; procedure Main is X : Float := 2.71; begin Ada.Text_IO.Put_Line (Float'Image (X)); end Main; Result 2.71000E+00

If a static constructor throws an exception, it is never retried. The type is unusable for the lifetime of the AppDomain. Any further usages of the type will raise a TypeInitializationException wrapped around the original exception. public class Animal { static Animal() { Consol...

It is unlikely for a developer to not come across a deprecated API during a development process. A deprecated program element is one that programmers are discouraged from using, typically because it is dangerous, or because a better alternative exists. Compilers and analyzers (like LINT) warn when a...

This is a huge topic, but it is also the most important "performance" issue. The main lesson for a novice is to learn of "composite" indexes. Here's a quick example: INDEX(last_name, first_name) is excellent for these: WHERE last_name = '...' WHERE first_name = '...' AND ...

innodb_buffer_pool_size should be about 70% of available RAM.

x IN ( SELECT ... ) turn into a JOIN When possible, avoid OR. Do not 'hide' an indexed column in a function, such as WHERE DATE(x) = ...; reformulate as WHERE x = ... You can generally avoid WHERE LCASE(name1) = LCASE(name2) by having a suitable collation. Do no use OFFSET for "paginatio...

Detailed instructions on getting material-design set up or installed.

You can change the url of an existing remote by the command git remote set-url remote-name url

Example below shows how to create a BroadcastReceiver which is able to receive BOOT_COMPLETED events. This way, you are able to start a Service or start an Activity as soon device was powered up. Also, you can use BOOT_COMPLETED events to restore your alarms since they are destroyed when device is ...

For the sake of this example, let us assume that we have a server for handling the POST requests that we will be making from our Android app: // User input data. String email = "[email protected]"; String password = "123"; // Our server URL for handling POST requests. String UR...

For a Django project with requirements and deployment tools under source control. This example builds upon concepts from the Two Scoops of Django. They have published a template: repository/ docs/ .gitignore project/ apps/ blog/ migrations/ ...

Casting: The Basics Casting is used to transform data from long to wide format. Starting with a long data set: DT = data.table(ID = rep(letters[1:3],3), Age = rep(20:22,3), Test = rep(c("OB_A","OB_B","OB_C"), each = 3), Result = 1:9) We can cast our data using the...

The FETCH clause was introduced in Oracle 12c R1: SELECT val FROM mytable ORDER BY val DESC FETCH FIRST 5 ROWS ONLY; An example without FETCH that works also in earlier versions: SELECT * FROM ( SELECT val FROM mytable ORDER BY val DESC ) WHERE ROWNUM <= 5;

One of the nicest features of flexbox is to allow optimally fitting containers to their parent element. Live demo. HTML: <div class="flex-container"> <div class="flex-item">1</div> <div class="flex-item">2</div> <div class=&q...

The pointer-events property allows for control over how HTML elements respond to mouse/touch events. .disabled { pointer-events: none; } In this example, 'none' prevents all click, state and cursor options on the specified HTML element [[1]] Other valid values for HTMl elements are: ...

Using outline: .div1{ border: 3px solid black; outline: 6px solid blue; width: 100px; height: 100px; margin: 20px; } Using box-shadow: .div2{ border: 5px solid green; box-shadow: 0px 0px 0px 4px #000; width: 100px; height: 100px; margin: 20px; } Using a ps...

2.12.2 You can use the minElement() and maxElement() methods to find the minimum or maximum element in a given sequence. For example, with an array of numbers: let numbers = [2, 6, 1, 25, 13, 7, 9] let minimumNumber = numbers.minElement() // Optional(1) let maximumNumber = numbers.maxElement()...

Often beginning MATLAB developers will use MATLAB's editor to write and edit code, in particular custom functions with inputs and outputs. There is a Run button at the top that is available in recent versions of MATLAB: Once the developer finishes with the code, they are often tempted to push th...

Here is typical error handler for a subform as a table: Public Const cErrCodeValueRequierd = 3162 Public Const cErrCodeDuplicateKey = 3022 Private Sub Form_Error(DataErr As Integer, Response As Integer) Select Case DataErr Case cErrCodeDuplicateKey MsgBox "Duplic...

To create a most basic test with Jasmine go to your spec (tests) folder and add file named testSpec.js. In that file add following: var request = require("request"); describe("Hello World Test", function() { // This is your test bundle describe("GET SO", fu...