Tutorial by Examples: nd

If you're doing multiple long calculations, you can run them at the same time on different threads on your computer. To do this, we make a new Thread and have it point to a different method. using System.Threading; class MainClass { static void Main() { var thread = new Thread(Seco...

Sometimes, you want your threads to simultaneously share data. When this happens it is important to be aware of the code and lock any parts that could go wrong. A simple example of two threads counting is shown below. Here is some dangerous (incorrect) code: using System.Threading; class MainCl...

Unlike Java, Dart doesn’t have the keywords public, protected, and private. If an identifier starts with an underscore _, it’s private to its library. If you for example have class A in a separate library file (eg, other.dart), such as: library other; class A { int _private = 0; testA()...

Parameters The first 4 parameters are passed in (in order) RCX, RDX, R8 and R9. XMM0 to XMM3 are used to pass floating point parameters. Any further parameters are passed on the stack. Parameters larger than 64bit are passed by address. Spill Space Even if the function uses less than 4 paramet...

You can use gradle to have BuildConfig constants and res values on a per flavor basis. Just add the value to the flavor you want to support. android { defaultConfig { resValue "string", "app_name", "Full App" buildConfigField "boolean",...

The Firebase Realtime Database allows ordering and querying data. For small data sizes, the database supports ad hoc querying, so indexes are generally not required during development. Before launching your app though, it is important to specify indexes for any queries you have to ensure they contin...

$ mkdir 20{09..11}-{01..12} Entering the ls command will show that the following directories were created: 2009-01 2009-04 2009-07 2009-10 2010-01 2010-04 2010-07 2010-10 2011-01 2011-04 2011-07 2011-10 2009-02 2009-05 2009-08 2009-11 2010-02 2010-05 2010-08 2010-11 2011-02 2011-05 2011-08 2011...

Just define: // These rules give anyone, even people who are not users of your app, // read and write access to your database { "rules": { ".read": true, ".write": true } } It can be useful during development but pay attention because This level o...

You can define a private rules to disable read and write access to your database by users. With these rules, you can only access the database when you have administrative privileges (which you can get by accessing the database through the Firebase console or by signing in from a server). // These...

An indeterminate ProgressBar shows a cyclic animation without an indication of progress. Basic indeterminate ProgressBar (spinning wheel) <ProgressBar android:id="@+id/progressBar" android:indeterminate="true" android:layout_width="wrap_content" ...

With more and more battery optimizations being put into the Android system over time, the methods of the AlarmManager have also significantly changed (to allow for more lenient timing). However, for some applications it is still required to be as exact as possible on all Android versions. The follow...

using the vibrate(long[] pattern, int repeat) Vibrator vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE); // Start time delay // Vibrate for 500 milliseconds // Sleep for 1000 milliseconds long[] pattern = {0, 500, 1000}; // 0 meaning is repeat indefinitely vibrator.vib...

Remember, all the best practices of typical web architecture still apply. For an excellent overview on the subject, please refer to Michael Nygard's excellent book Release It! Design and Deploy Production-Ready Software. Writing your app in Meteor doesn't absolve you of auditing third party librarie...

You can use Bash Parameter Expansion to emulate common filename-processing operations like basename and dirname. We will use this as our example path: FILENAME="/tmp/example/myfile.txt" To emulate dirname and return the directory name of a file path: echo "${FILENAME%/*}" ...

Another use of RODBC is in connecting with SQL Server Management Database. We need to specify the 'Driver' i.e. SQL Server here, the database name "Atilla" and then use the sqlQuery to extract either the full table or a fraction of it. library(RODBC) cn <- odbcDriverConnect(connect...

Variables in Visual Basic are declared using the Dim keyword. For example, this declares a new variable called counter with the data type Integer: Dim counter As Integer A variable declaration can also include an access modifier, such as Public, Protected, Friend, or Private. This works in conju...

# application.rb config.time_zone = 'Eastern Time (US & Canada)' config.active_record.default_timezone = :local

This is the code for changing output application file name (.apk). The name can be configured by assigning a different value to newName android { applicationVariants.all { variant -> def newName = "ApkName"; variant.outputs.each { output -> def ...

In some cases it is necessary to calculate a variable amount of values on separate Futures. Assume to have a List[Future[Int]], but instead a List[Int] needs to be processed. Then the question is how to turn this instance of List[Future[Int]] into a Future[List[Int]]. For this purpose there is the s...

Keeping a GUI responsive while running a lengthy process requires either some very elaborate "callbacks" to allow the GUI to process its message queue, or the use of (background) (worker) threads. Kicking off any number of threads to do some work usually isn't a problem. The fun starts wh...