Tutorial by Examples: s

Entity Framework exposes abstraction classes that are used to interact with underlying databases in the form of classes like DbContext. These contexts generally consist of DbSet<T> properties that expose the available collections that can be queried : public class ExampleContext: DbContext ...

A Connection String is a string that specifies information about a particular data source and how to go about connecting to it by storing credentials, locations, and other information. Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword; Storing Your Connection Stri...

You can combine named arguments with optional parameters. Let see this method: public sealed class SmsUtil { public static bool SendMessage(string from, string to, string message, int retryCount = 5, object attachment = null) { // Some code } } When you want to call t...

You can place named arguments in any order you want. Sample Method: public static string Sample(string left, string right) { return string.Join("-",left,right); } Call Sample: Console.WriteLine (Sample(left:"A",right:"B")); Console.WriteLine (Sample(right...

LocalDate tomorrow = LocalDate.now().plusDays(1); LocalDateTime anHourFromNow = LocalDateTime.now().plusHours(1); Long daysBetween = java.time.temporal.ChronoUnit.DAYS.between(LocalDate.now(), LocalDate.now().plusDays(3)); // 3 Duration duration = Duration.between(Instant.now(), ZonedDateTime.par...

Represents an instant in time. Can be thought of as a wrapper around a Unix timestamp. Instant now = Instant.now(); Instant epoch1 = Instant.ofEpochMilli(0); Instant epoch2 = Instant.parse("1970-01-01T00:00:00Z"); java.time.temporal.ChronoUnit.MICROS.between(epoch1, epoch2); // 0

The zip function accepts 2 parameters of type SequenceType and returns a Zip2Sequence where each element contains a value from the first sequence and one from the second sequence. Example let nums = [1, 2, 3] let animals = ["Dog", "Cat", "Tiger"] let numsAndAnimals ...

stats::heatmap Example 1 (Basic usage) require(graphics); require(grDevices) x <- as.matrix(mtcars) rc <- rainbow(nrow(x), start = 0, end = .3) cc <- rainbow(ncol(x), start = 0, end = .3) hv <- heatmap(x, col = cm.colors(256), scale = "column", RowSideColo...

Compiler definitions run platform specific code. Using them you can make small differences between various platforms. Trigger Game Center achievements on apple devices and google play achievements on Android devices. Change the icons in menus (windows logo in windows, Linux penguin in Linux). P...

defaultProps allows you to set default prop values for your component. In the below example if you do not pass the name props, it will display John otherwise it will display the passed value class Example extends Component { render() { return ( <View> <Text>{this...

What is an enter selection? In D3.js, when one binds data to DOM elements, three situations are possible: The number of elements and the number of data points are the same; There are more elements than data points; There are more data points than elements; In the situation #3, all the data ...

If you are behind a proxy, you have to tell git about it: git config --global http.proxy http://my.proxy.com:portnumber If you are no more behind a proxy: git config --global --unset http.proxy

layer.masksToBounds = true; layer.cornerRadius = 8;

You can build the cross-platform "Hello World" C++ code, using Scons - A Python-language software construction tool. First, create a file called SConstruct (note that SCons will look for a file with this exact name by default). For now, the file should be in a directory right along your h...

foreach varlist1 list1 ?varlist2 list2 ...? body foreach is a powerful control structure that allows looping over a list or multiple lists. set alpha [list a b c d e f] foreach {key} $alpha { puts "key: $key" } Multiple variable names may be specified. set alphaindexes [list a ...

Subclassing also Subclasses Singleton Class class Example end Example.singleton_class #=> #<Class:Example> def Example.foo :example end class SubExample < Example end SubExample.foo #=> :example SubExample.singleton_class.superclass #=> #<Class:Example> ...

Instances never contain a method they only carry data. However we can define a singleton class for any object including an instance of a class. When a message is passed to an object (method is called) Ruby first checks if a singleton class is defined for that object and if it can reply to that mess...

There are three ways to reopen a Singleton Class Using class_eval on a singleton class. Using class << block. Using def to define a method on the object's singleton class directly class Example end Example.singleton_class.class_eval do def foo :foo end end Example.fo...

A Semaphore is a high-level synchronizer that maintains a set of permits that can be acquired and released by threads. A Semaphore can be imagined as a counter of permits that will be decremented when a thread acquires, and incremented when a thread releases. If the amount of permits is 0 when a thr...

Attributes are global state (*). If they were implemented in JavaScript they would look something like this // pseudo code gl = { ARRAY_BUFFER: null, vertexArray: { attributes: [ { enable: ?, type: ?, size: ?, normalize: ?, stride: ?, offset: ?, buffer: ? }, { enabl...