Tutorial by Examples: comp

The Composite pattern is a design pattern that allows to treat a group of objects as a single instance of an object. It is one of the Gang of Four's structural design patterns. Example below demonstrate how Composite can be used to log to multiple places using single Log invocation. This approach a...

By using the .HasKey() method, a set of properties can be explicitly configured as the composite primary key of the entity. using System.Data.Entity; // .. public class PersonContext : DbContext { // .. protected override void OnModelCreating(DbModelBuilder modelBuilder) {...

-- composite key - using two or more existing columns within a table to create a primary key create table person ( firstName varchar(100) not null, lastName varchar(100) not null, dob DateTime not null, ssn varchar(9) not null, primary key (firstName, lastName, dob) )

The regular composition works for unary functions. In the case of binary, we can define (f .: g) x y = f (g x y) -- which is also = f ((g x) y) = (f . g x) y -- by definition of (.) = (f .) (g x) y = ((f .) . g) x y Thus,...

In order to use compression over the wire for a faster transfer, pass the --compress option to mysqldump. Example: mysqldump -h db.example.com -u username -p --compress dbname > dbname.sql Important: If you don't want to lock up the source db, you should also include --lock-tables=false. But ...

gunzip -c dbname.sql.gz | mysql dbname -u username -p Note: -c means write output to stdout.

NSURL *url = [NSURL URLWithString:@"http://www.example.com/images/apple-tree.jpg"]; NSString *fileName = [url lastPathComponent]; // fileName = "apple-tree.jpg"

Interfaces can seem abstract until you seem them in practice. The IComparable and IComparable<T> are great examples of why interfaces can be helpful to us. Let's say that in a program for a online store, we have a variety of items you can buy. Each item has a name, an ID number, and a price. ...

Most websites require a much more complicated process than the one demonstrated above. Common steps for logging into a website are: Get the unique cookie from the initial login form. Inspect the login form to see what the destination url is for the authentication request Parse the login form t...

Enables a code to be statically compiled. Its bytecode will be closer to Java's, thus having better performance, though some dynamic features won't be available. @groovy.transform.CompileStatic class ListMath { def countSize(List<String> strings) { strings.collect { it.size() }...

A common mistake for Java beginners is to use the == operator to test if two strings are equal. For example: public class Hello { public static void main(String[] args) { if (args.length > 0) { if (args[0] == "hello") { System.out.println(&q...

In Object Oriented Programming a common task is to compose objects (values). In Functional Programming it is as common task to compose values as well as functions. We are used to compose values from our experience of other programming languages using operators like +, -, *, / and so on. Value co...

C# using OpenQA.Selenium using OpenQA.Selenium.Chrome; using System.Threading; namespace WebDriver Tests { class WebDriverWaits { static void Main() { IWebDriver driver = new ChromeDriver(@"C:\WebDriver"); driver.Na...

If you wish to make a complete backup of a large MySql installation and do not have sufficient local storage, you can dump and compress it directly to an Amazon S3 bucket. It's also a good practice to do this without having the DB password as part of the command: mysqldump -u root -p --host=localho...

The following output equivalent results: class IfElseExample { public string DebugToString(object a) { if (a is StringBuilder) { return DebugToStringInternal(a as StringBuilder); } else if (a is List<string>) { ...

template <div id="demo">{{fullName}}</div> watch example var vm = new Vue({ el: '#demo', data: { firstName: 'Foo', lastName: 'Bar', fullName: 'Foo Bar' } }) vm.$watch('firstName', function (val) { this.fullName = val + ' ' + this.lastName })...

@Singleton @Component(modules = AppModule.class) public interface AppComponent { void inject(App app); Context provideContext(); Gson provideGson(); MainActivityComponent mainActivityComponent(ActivityModule activityModule); } @ActivityScope @Subcomponent(modules = Act...

var source = new AutoCompleteStringCollection(); // Add your collection of strings. source.AddRange(new[] { "Guybrush Threepwood", "LeChuck" }); var textBox = new TextBox { AutoCompleteCustomSource = source, AutoCompleteMode = AutoCompleteMode.SuggestAppend, ...

long fib(long n) { return n < 2 ? n : fib(n - 1) + fib(n - 2); } struct FibStruct(int n) { // Remarks: n is a template ubyte[fib(n)] data; } void main() { import std.stdio : writeln; enum f10 = fib(10); // execute the function at compile-time pragma(msg, f10); /...

In F# there are many options for creating data pipelines, for example: List, Seq and Array. What data pipeline is preferable from memory usage and performance perspective? In order to answer this we'll compare performance and memory usage using different pipelines. Data Pipeline In order to me...