Tutorial by Examples

Polymorphism without inheritance in the form of duck typing as available in Python due to its dynamic typing system. This means that as long as the classes contain the same methods the Python interpreter does not distinguish between them, as the only checking of the calls occurs at run-time. class ...

While catching the Throwable, Exception, Error and RuntimeException exceptions is bad, throwing them is even worse. The basic problem is that when your application needs to handle exceptions, the presence of the top level exceptions make it hard to discriminate between different error conditions. ...

Controls how the image should be resized or moved to match the size of ImageView. XML attribute: android:scaleType="..." i will illustrate different scale types with a square ImageView which has a black background and we want to display a rectangular drawable in white background in Im...

Set a tinting color for the image. By default, the tint will blend using SRC_ATOP mode. set tint using XML attribute: android:tint="#009c38" Note: Must be a color value, in the form of "#rgb", "#argb", "#rrggbb", or "#aarrggbb". set tint progra...

SELECT * INTO NewTable FROM OldTable Creates a new table with structure of old table and inserts all rows into the new table. Some Restrictions You cannot specify a table variable or table-valued parameter as the new table. You cannot use SELECT…INTO to create a partitioned table, even whe...

The following example can be used to find the total row count for a specific table in a database if table_name is replaced by the the table you wish to query: SELECT COUNT(*) AS [TotalRowCount] FROM table_name; It is also possible to get the row count for all tables by joining back to the table'...

This is something that can be frustrating: you make a visualisation using D3.js but the rectangle you want on top is hidden behind another rectangle, or the line you planned to be behind some circle is actually over it. You try to solve this using the z-index in your CSS, but it doesn't work (in SVG...

enum Fruit { apple, banana } main() { var a = Fruit.apple; switch (a) { case Fruit.apple: print('it is an apple'); break; } // get all the values of the enums for (List<Fruit> value in Fruit.values) { print(value); } // get the second val...

First of all, ensure that you've enabled the 'Virtualization' in your BIOS setup. Start the Android SDK Manager, select Extras and then select Intel Hardware Accelerated Execution Manager and wait until your download completes. If it still doesn't work, open your SDK folder and run /extras/intel/Ha...

adb shell am start -n com.android.settings/.DevelopmentSettings Will navigate your device/emulator to the Developer Options section.

This is relevant for apps that implement a BootListener. Test your app by killing your app and then test with: adb shell am broadcast -a android.intent.action.BOOT_COMPLETED -c android.intent.category.HOME -n your.app/your.app.BootListener (replace your.package/your.app.BootListener with proper ...

First define an ExitActivity in the AndroidManifest.xml <activity android:name="com.your_example_app.activities.ExitActivity" android:autoRemoveFromRecents="true" android:theme="@android:style/Theme.NoDisplay" /> Afterwards the ExitA...

Detailed instructions on getting azure-service-fabric set up or installed.

Rather than passing a static string as a predicate's criteria. It is possible to substitute values by using format specifiers. There are five format specifiers: %K is a var arg substitution for a key path. %@ is a var arg substitution for an object value-often a string, number, date, or an array...

When we are working on a framework, if the constraints are not too complex, we'd better use Interface Builder or NSLayoutConstraint in code to make it smaller enough, instead of import Masonry or SnapKit. for example: Objective-C // 1. create views UIView *blueView = [[UIView alloc...

Swift classes supports having multiple ways of being initialized. Following Apple's specs this 3 rules must be respected: A designated initializer must call a designated initializer from its immediate superclass. A convenience initializer must call another initializer from the same class. A ...

let data = [1; 2; 3; 4; 5;] let repeating = seq {while true do yield! data} Repeating sequences can be created using a seq {} computation expression

std::function type erases down to a few operations. One of the things it requires is that the stored value be copyable. This causes problems in a few contexts, like lambdas storing unique ptrs. If you are using the std::function in a context where copying doesn't matter, like a thread pool where ...

When factors are created with defaults, levels are formed by as.character applied to the inputs and are ordered alphabetically. charvar <- rep(c("W", "n", "c"), times=c(17,20,14)) f <- factor(charvar) levels(f) # [1] "c" "n" "W" ...

/** * Created by Nick Cardoso on 03/08/16. * This is not a complete parcelable implementation, it only highlights the easiest * way to read and write your Enum values to your parcel */ public class Foo implements Parcelable { private final MyEnum myEnumVariable; private final M...