Tutorial by Examples: f

// long form String sayHello(String name){ "Hello, ${name ? name : 'stranger'}." } // elvis String sayHello(String name){ "Hello, ${name ?: 'stranger'}." } Notice that the "elvis" format omits the "true" term because the original comparison...

The example below shows how to add a navigation bar button (called a UIBarButtonItem) in the Interface Builder. Add a Navigation Controller to your Storyboard Select your View Controller and then in the Xcode menu choose Editor > Embed In > Navigation Controller. Alternatively, you could ...

Below is an example of a pure Xamarin Forms custom control. No custom rendering is being done for this but could easily be implemented, in fact, in my own code, I use this very same control along with a custom renderer for both the Label and Entry. The custom control is a ContentView with a Label, ...

When you have a zoomed Image (or other content) you may want to drag around the Image to show all of its content in the zoomed in state. This can be achieved by implementing the PanGestureRecognizer. From code this looks like so: var panGesture = new PanGestureRecognizer(); panGesture.PanUpdated...

You can simply use the native map APIs on each platform with Xamarin Forms. All you need is to download the Xamarin.Forms.Maps package from nuget and install it to each project (including the PCL project). Maps Initialization First of all you have to add this code to your platform-specific project...

Using the System.String.Contains you can find out if a particular string exists within a string. The method returns a boolean, true if the string exists else false. string s = "Hello World"; bool stringExists = s.Contains("ello"); //stringExists =true as the string contains t...

The System.String.Trim method can be used to remove all leading and trailing white-space characters from a string: string s = " String with spaces at both ends "; s = s.Trim(); // s = "String with spaces at both ends" In addition: To remove white-space only fro...

The System.String.Join method allows to concatenate all elements in a string array, using a specified separator between each element: string[] words = {"One", "Two", "Three", "Four"}; string singleString = String.Join(",", words); // singleString =...

In some cases we need to apply functions to a set of ND-arrays. Let's look at this simple example. A(:,:,1) = [1 2; 4 5]; A(:,:,2) = [11 22; 44 55]; B(:,:,1) = [7 8; 1 2]; B(:,:,2) = [77 88; 11 22]; A = ans(:,:,1) = 1 2 4 5 ans(:,:,2) = 11 22 44 55 >&...

Let's look at a sample of logging which you can see in many programs: public class LoggingComplex { private static final Logger logger = Logger.getLogger(LoggingComplex.class.getName()); private int total = 50, orders = 20; private String username = "Bob";...

Add the required network permissions to the application manifest file: <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android....

Add below dependencies to your build.gradle // Facebook login compile 'com.facebook.android:facebook-android-sdk:4.21.1' Add below helper class to your utility package: /** * Created by Andy * An utility for Facebook */ public class FacebookSignInHelper { private static final...

The %s conversion of printf states that the corresponding argument a pointer to the initial element of an array of character type. A null pointer does not point to the initial element of any array of character type, and thus the behavior of the following is undefined: char *foo = NULL; printf(&quo...

With this example, you will be able to perform following operations: Connect to Firebase Storage Create a directory named “images” Upload a file in images directory Download a file from images directory Delete a file from images directory public class MainActivity extends AppCompatActivity...

Thanks to type-inference and partial application in F# data-driven programming is succinct and readable. Let's imagine we are selling car insurance. Before we try selling it to a customer, we try to determine if the customer is a valid potential customer for our company by checking the customer's ...

private boolean unpackZip(String path, String zipname){ InputStream is; ZipInputStream zis; try { String filename; is = new FileInputStream(path + zipname); zis = new ZipInputStream(new BufferedInputStream(is)); ZipEntry ze; byte[] buffer = new...

If you want to migrate from existing log4j 1.x in your project to log4j 2.x then remove all existing log4j 1.x dependencies and add the following dependency: Log4j 1.x API Bridge Maven Build <dependencies> <dependency> <groupId>org.apache.logging.log4j</groupId> ...

Starting from a dataframe df: U L 111 en 112 en 112 es 113 es 113 ja 113 zh 114 es Imagine you want to add a new column called S taking values from the following dictionary: d = {112: 'en', 113: 'es', 114: 'es', 111: 'en'} You can use map to perform a lookup on keys returni...

Query can be used instead of table in import operation: sqoop import --query 'select Id,Message from TestTable where $CONDITIONS' --where 'id>100' --connect "jdbc:sqlserver://192.168.1.100:1433;database=Test_db --username user -–pas...

Streams, and especially IntStreams, are an elegant way of implementing summation terms (∑). The ranges of the Stream can be used as the bounds of the summation. E.g., Madhava's approximation of Pi is given by the formula (Source: wikipedia): This can be calculated with an arbitrary precision. E....