Tutorial by Examples: b

You send the query as a string and in response callback with the answer is received. The callback gives you error, array of rows and fields. Each row contains all the column of the returned table. Here is a snippet for the following explanation. connection.query('SELECT name,email from users', fu...

git checkout --orphan new-orphan-branch The first commit made on this new branch will have no parents and it will be the root of a new history totally disconnected from all the other branches and commits. source

Another example of "Hello World" style programs is FizzBuzz. This is one example of a FizzBuzz implementation. Very idiomatic Go in play here. package main // Simple fizzbuzz implementation import "fmt" func main() { for i := 1; i <= 100; i++ { s := &qu...

You can use any element as an handle to drag another element around: <script> $(function() { $( "#draggable" ).draggable({ handle: ".handle" }); }); </script> <div id="draggable"> <span class="handle"&...

This method is called by var_dump() when dumping an object to get the properties that should be shown. If the method isn't defined on an object, then all public, protected and private properties will be shown. — PHP Manual class DeepThought { public function __debugInfo() { return...

Subclassing UIControl gives us access to the following methods: beginTrackingWithTouch is called when the finger first touches down within the control's bounds. continueTrackingWithTouch is called repeatedly as the finger slides across the control and even outside of the control's bounds. endTr...

There are several ways to create an Observable in RxJava. The most powerful way is to use the Observable.create method. But it's also the most complicated way. So you must avoid using it, as much as possible. Emitting an exiting value If you already have a value, you can use Observable.just to emi...

Create a class which extends Service class and in overridden method onBind return your local binder instance: public class LocalService extends Service { // Binder given to clients private final IBinder mBinder = new LocalBinder(); /** * Class used for the client Binder. Bec...

Perform a basic GET request and prints the contents of a site (HTML). package main import ( "fmt" "io/ioutil" "net/http" ) func main() { resp, err := http.Get("https://example.com/") if err != nil { panic(err) } ...

You can reboot your device by executing the following command: adb reboot Perform this command to reboot into bootloader: adb reboot bootloader Reboot to recovery mode: adb reboot recovery Be aware that the device won't shutdown first!

An algorithmic problem is specified by describing the complete set of instances it must work on and of its output after running on one of these instances. This distinction, between a problem and an instance of a problem, is fundamental. The algorithmic problem known as sorting is defined as follows:...

__FUNCTION__ returns only the name of the function whereas __METHOD__ returns the name of the class along with the name of the function: <?php class trick { public function doit() { echo __FUNCTION__; } public function doitagain() { echo __METHOD_...

__CLASS__ magic constant returns the same result as get_class() function called without parameters and they both return the name of the class where it was defined (i.e. where you wrote the function call/constant name ). In contrast, get_class($this) and get_called_class() functions call, will both ...

To switch between time zones, you need datetime objects that are timezone-aware. from datetime import datetime from dateutil import tz utc = tz.tzutc() local = tz.tzlocal() utc_now = datetime.utcnow() utc_now # Not timezone-aware. utc_now = utc_now.replace(tzinfo=utc) utc_now # Timezon...

Support for type hinting array parameters (and return values after PHP 7.1) was added in PHP 5.1 with the keyword array. Any arrays of any dimensions and types, as well as empty arrays, are valid values. Support for type hinting callables was added in PHP 5.4. Any value that is_callable() is valid ...

Since PHP objects don't inherit from any base class (including stdClass), there is no support for type hinting a generic object type. For example, the below will not work. <?php function doSomething(object $obj) { return $obj; } class ClassOne {} class ClassTwo {} $classOne= new...

const fs = require('fs'); const readline = require('readline'); const rl = readline.createInterface({ input: fs.createReadStream('text.txt') }); // Each new line emits an event - every time the stream receives \r, \n, or \r\n rl.on('line', (line) => { console.log(line); }); ...

Sometimes you may want to bypass an alias temporarily, without disabling it. To work with a concrete example, consider this alias: alias ls='ls --color=auto' And let's say you want to use the ls command without disabling the alias. You have several options: Use the command builtin: command...

[alias] logp=log --pretty=format:'%h %ad | %s%d [%an]' --graph --date=short lg = log --graph --date-order --first-parent \ --pretty=format:'%C(auto)%h%Creset %C(auto)%d%Creset %s %C(green)(%ad) %C(bold cyan)<%an>%Creset' lgb = log --graph --date-order --branches --first-paren...

Adding the DebuggerDisplay Attribute will change the way the debugger displays the class when it is hovered over. Expressions that are wrapped in {} will be evaluated by the debugger. This can be a simple property like in the following sample or more complex logic. [DebuggerDisplay("{StringPr...