Tutorial by Examples: d

Using ActiveCell or ActiveSheet can be source of mistakes if (for any reason) the code is executed in the wrong place. ActiveCell.Value = "Hello" 'will place "Hello" in the cell that is currently selected Cells(1, 1).Value = "Hello" 'will always place "Hello&...

Uploading Files Uploading files in Yii is usually done with the help of [[yii\web\UploadedFile]] which encapsulates each uploaded file as an UploadedFile object. Combined with [[yii\widgets\ActiveForm]] and models, you can easily implement a secure file uploading mechanism. Creating Models Lik...

So you've uploaded your files to a folder say /backend/web/uploads/ and you want these uploads to be visible on the frontend too. The easiest option is to create a symlink in the frontend that links to the backend: ln -s /path/to/backend/web/uploads/ /path/to/frontend/web/uploads In your views y...

The <algorithm> header provides a number of useful functions for working with sorted vectors. An important prerequisite for working with sorted vectors is that the stored values are comparable with <. An unsorted vector can be sorted by using the function std::sort(): std::vector<int&...

() is a Monoid. Since there is only one value of type (), there's only one thing mempty and mappend could do: instance Monoid () where mempty = () () `mappend` () = ()

To create the classic "Hello, world" printing program, create a file called hello.d with a text editor containing the following code : import std.stdio; void main() { writeln("Hello, World!"); //writeln() automatically adds a newline (\n) to the output } Explanati...

SharedPreferences allows you to store primitive data types only (boolean, float, long, int, String, and string set). You cannot store more complex objects in SharedPreferences, and as such is really meant to be a place to store user settings or similar, it's not meant to be a database to keep user d...

public class Customer { public void SendEmail() { // Sending email code here } } List<Customer> customers = new List<Customer>(); customers.Add(new Customer()); customers.Add(new Customer()); customers.ForEach(c => c.SendEmail());

ForEach() is defined on the List<T> class, but not on IQueryable<T> or IEnumerable<T>. You have two choices in those cases: ToList first The enumeration (or query) will be evaluated, copying the results into a new list or calling the database. The method is then called on each it...

If you need to count distinct characters then, for the reasons explained in Remarks section, you can't simply use Length property because it's the length of the array of System.Char which are not characters but code-units (not Unicode code-points nor graphemes). If, for example, you simply write tex...

We cannot break a string into arbitrary points (because a System.Char may not be valid alone because it's a combining character or part of a surrogate) then code must take that into account (note that with length I mean the number of graphemes not the number of code-units): public static IEnumerabl...

.NET strings contain System.Char (UTF-16 code-units). If you want to save (or manage) text with another encoding you have to work with an array of System.Byte. Conversions are performed by classes derived from System.Text.Encoder and System.Text.Decoder which, together, can convert to/from another ...

There is no need to create the whole UI in a single FXML using a single controller. The <fx:include> tag can be used to include one fxml file into another. The controller of the included fxml can be injected into the controller of the including file just as any other object created by the FXM...

Sometimes a element needs to be created outside of the usual object structure in the fxml. This is where Define Blocks come into play: Contents inside a <fx:define> element are not added to the object created for the parent element. Every child element of the <fx:define> needs a fx:id...

The following example encrypts data by using a hybrid cryptosystem consisting of AES GCM and OAEP, using their default parameter sizes and an AES key size of 128 bits. OAEP is less vulnerable to padding oracle attacks than PKCS#1 v1.5 padding. GCM is also protected against padding oracle attacks. ...

Long-running operations must not be run on the JavaFX application thread, since this prevents JavaFX from updating the UI, resulting in a frozen UI. Furthermore any change to a Node that is part of a "live" scene graph must happen on the JavaFX application thread. Platform.runLater can be...

vim is a modal editor. This means that at any time inside a vim session, the user is going to be in one of the modes of operation. Each one of offers a different set commands, operations, key bindings... Normal mode (or Command mode) The mode vim starts in. From other modes, usually accessible ...

The below examples use the new form API introduced in RC3. pw-change.template.html <form class="container" [formGroup]="pwChangeForm"> <label for="current">Current Password</label> <input id="current" formControlName="curr...

import pandas as pd chunksize = [n] for chunk in pd.read_csv(filename, chunksize=chunksize): process(chunk) delete(chunk)

Multidimensional arrays are basically arrays containing others arrays as elements. It is represented like [sizeDim1][sizeDim2]..[sizeLastDim]type, replacing sizeDim by numbers corresponding to the length of the dimention, and type by the type of data in the multidimensional array. For example, [2]...