Tutorial by Examples: er

First Initialize FirebaseDatabase: FirebaseDatabase database = FirebaseDatabase.getInstance(); Write to your database: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRef....

You can retrieve the data stored at the located referenced by the pointer variable, using the ToString() method. The following example demonstrates this: using System; namespace UnsafeCodeApplication { class Program { public static void Main() { unsafe { ...

You can pass a pointer variable to a method as parameter. The following example illustrates this: using System; namespace UnsafeCodeApplication { class TestPointer { public unsafe void swap(int* p, int *q) { int temp = *p; *p = *q; *q = temp; ...

In C#, an array name and a pointer to a data type same as the array data, are not the same variable type. For example, int *p and int[] p, are not same type. You can increment the pointer variable p because it is not fixed in memory but an array address is fixed in memory, and you can't increment th...

Simple single port RAM with async read/write operations module ram_single_port_ar_aw #( parameter DATA_WIDTH = 8, parameter ADDR_WITDH = 3 )( input we, // write enable input oe, // output enable input [(ADDR_WITDH-1):0] waddr, // ...

a Character evaluates to true if it's value is not zero, false if zero assert ! new Character((char)0) assert ! new Character('\u0000Hello Zero Char'.charAt(0)) assert new Character('Hello'.charAt(0))

a Matcher evaluates to true if it can find at least one match, false if no match is found // a match is found => true assert 'foo' =~ /[a-z]/ // the regexp does not match fully => no match => false assert !( 'foo' ==~ /[a-z]/ ) // a match is found => true assert 'foo' =~ /o/ // no...

MERGE INTO targetTable t USING sourceTable s ON t.PKID = s.PKID WHEN MATCHED AND NOT EXISTS ( SELECT s.ColumnA, s.ColumnB, s.ColumnC INTERSECT SELECT t.ColumnA, t.ColumnB, s.ColumnC ) THEN UPDATE SET t.Colum...

This example demonstrates how pointers can be used for C-like access to C# arrays. unsafe { var buffer = new int[1024]; fixed (int* p = &buffer[0]) { for (var i = 0; i < buffer.Length; i++) { *(p + i) = i; } } } The unsafe keyw...

Addition and subtraction in pointers works differently from integers. When a pointer is incremented or decremented, the address it points to is increased or decreased by the size of the referent type. For example, the type int (alias for System.Int32) has a size of 4. If an int can be stored in add...

In C and C++, the asterisk in the declaration of a pointer variable is part of the expression being declared. In C#, the asterisk in the declaration is part of the type. In C, C++ and C#, the following snippet declares an int pointer: int* a; In C and C++, the following snippet declares an int ...

C# inherits from C and C++ the usage of the symbol -> as a means of accessing the members of an instance through a typed pointer. Consider the following struct: struct Vector2 { public int X; public int Y; } This is an example of the usage of -> to access its members: Vector2...

The criteria that a type must satisfy in order to support pointers (see Remarks) cannot be expressed in terms of generic constraints. Therefore, any attempt to declare a pointer to a type provided through a generic type parameter will fail. void P<T>(T obj) where T : struct { T* p...

You can create your own implementation of IDatabaseInitializer. Example implementation of an initializer, that will migrate the database to 0 and then migrate all the way to the newest migration (usefull e.g. when running integration tests). In order to do that you would need a DbMigrationsConfigur...

An implementation of IDatabaseInitializer that will use Code First Migrations to update the database to the latest version. To use this initializer you have to use DbMigrationsConfiguration type too. Usage: public class MyContext : DbContext { public MyContext() { Database.SetInitial...

CREATE TABLE [dbo].[MemOptimizedTemporalTable] ( [BusinessDocNo] [bigint] NOT NULL, [ProductCode] [int] NOT NULL, [UnitID] [tinyint] NOT NULL, [PriceID] [tinyint] NOT NULL, [SysStartTime] [datetime2](7) GENERATED ALWAYS AS ROW START NOT NULL, [SysEndTime] [datetime2](7...

While the if ()... else statement allows to define only one (default) behaviour which occurs when the condition within the if () is not met, chaining two or more if () ... else statements allow to define a couple more behaviours before going to the last else branch acting as a "default", i...

In .NET, the GC allocates objects when there are no references left to them. Therefore, while an object can still be reached from code (there is a strong reference to it), the GC will not allocate this object. This can become a problem if there are a lot of large objects. A weak reference is a ref...

Plenty has been written about Python's GIL. It can sometimes cause confusion when dealing with multi-threaded (not to be confused with multiprocess) applications. Here's an example: import math from threading import Thread def calc_fact(num): math.factorial(num) num = 600000 t = Threa...

In most object oriented languages, allocating memory for an object and initializing it is an atomic operation: // Both allocates memory and calls the constructor MyClass object = new MyClass(); In Objective-C, these are separate operations. The class methods alloc (and its historic sibling allo...