Tutorial by Examples: b

To explicitly declare variables in VBA, use the Dim statement, followed by the variable name and type. If a variable is used without being declared, or if no type is specified, it will be assigned the type Variant. Use the Option Explicit statement on first line of a module to force all variables t...

7 Object spreading is just syntactic sugar for Object.assign({}, obj1, ..., objn); It is done with the ... operator: let obj = { a: 1 }; let obj2 = { ...obj, b: 2, c: 3 }; console.log(obj2); // { a: 1, b: 2, c: 3 }; As Object.assign it does shallow merging, not deep merging. let obj3 = ...

URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); try { BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // use a string builder to bufferize the response body //...

// Create a block with an asynchronous action var block = new ActionBlock<string>(async hostName => { IPAddress[] ipAddresses = await Dns.GetHostAddressesAsync(hostName); Console.WriteLine(ipAddresses[0]); }); block.Post("google.com"); // Post items to the block's ...

var httpClient = new HttpClient(); // Create a block the accepts a uri and returns its contents as a string var downloaderBlock = new TransformBlock<string, string>( async uri => await httpClient.GetStringAsync(uri)); // Create a block that accepts the content and prints it to t...

There are two Dockerfile directives to specify what command to run by default in built images. If you only specify CMD then docker will run that command using the default ENTRYPOINT, which is /bin/sh -c. You can override either or both the entrypoint and/or the command when you start up the built im...

Docker is supported on the following 64-bit versions of Ubuntu Linux: Ubuntu Xenial 16.04 (LTS) Ubuntu Wily 15.10 Ubuntu Trusty 14.04 (LTS) Ubuntu Precise 12.04 (LTS) A couple of notes: The following instructions involve installation using Docker packages only, and this ensures obtaining...

Any Chrome extension starts as an unpacked extension: a folder containing the extension's files. One file it must contain is manifest.json, which describes the basic properties of the extension. Many of the properties in that file are optional, but here is an absolute minimum manifest.json file: ...

Use pip to install Flask in a virtualenv. pip install flask Step by step instructions for creating a virtualenv for your project: mkdir project && cd project python3 -m venv env # or `virtualenv env` for Python 2 source env/bin/activate pip install flask Never use sudo pip in...

Rename the branch you have checked out: git branch -m new_branch_name Rename another branch: git branch -m branch_you_want_to_rename new_branch_name

A Table View is a list of rows that can be selected. Each row is populated from a data source. This example creates a simple table view in which each row is a single line of text. Add a UITableView to your Storyboard Although there are a number of ways to create a UITableView, one of the easiest...

The CREATE TABLE statement is used to create a table in a MySQL database. CREATE TABLE Person ( `PersonID` INTEGER NOT NULL PRIMARY KEY, `LastName` VARCHAR(80), `FirstName` VARCHAR(80), `Address` TEXT, `City` VARCHAR(100) ) Engine=InnoDB; Ev...

CREATE TABLE Person ( PersonID INT UNSIGNED NOT NULL, LastName VARCHAR(66) NOT NULL, FirstName VARCHAR(66), Address VARCHAR(255), City VARCHAR(66), PRIMARY KEY (PersonID) ); A primary key is a NOT NULL single or a multi-column identifier whic...

CREATE TABLE Account ( AccountID INT UNSIGNED NOT NULL, AccountNo INT UNSIGNED NOT NULL, PersonID INT UNSIGNED, PRIMARY KEY (AccountID), FOREIGN KEY (PersonID) REFERENCES Person (PersonID) ) ENGINE=InnoDB; Foreign key: A Foreign Key (FK) is either a single col...

5 <input type="number" value="0" name="quantity"> The Input element with a type attribute whose value is number represents a precise control for setting the element’s value to a string representing a number. Please note that this field does not guarantee to h...

To show all staged and unstaged changes, use: git diff HEAD NOTE: You can also use the following command: git status -vv The difference being that the output of the latter will actually tell you which changes are staged for commit and which are not.

A table can be replicated as follows: CREATE TABLE ClonedPersons LIKE Persons; The new table will have exactly the same structure as the original table, including indexes and column attributes. As well as manually creating a table, it is also possible to create table by selecting data from anot...

Method 1: Below query will be applicable for SQL Server 2000+ version (Contains 12 columns) SELECT * FROM dbo.sysdatabases Method 2: Below query extract information about databases with more informations (ex: State, Isolation, recovery model etc.) Note: This is a catalog view and will be availa...

First we need to install composer. Steps to install composer Install Composer. curl -sS https://getcomposer.org/installer | php Now change directory: sudo mv composer.phar /usr/local/bin/composer Check composer working composer Now Composer installed. There two ways to install Yii2 adv...

One of the most common misconceptions about OpenGL is, that it were a library that could be installed from 3rd party sources. This misconception leads to many questions in the form "how to I install OpenGL" or "where to download the OpenGL SDK". This is not how OpenGL finds the ...