In its most basic form, an object that implements IEnumerable represents a series of objects. The objects in question can be iterated using the c# foreach keyword.
In the example below, the object sequenceOfNumbers implements IEnumerable. It represents a series of integers. The foreach loop iterate...
ALTER TABLE EMPLOYEES ADD pk_EmployeeID PRIMARY KEY (ID)
This will add a Primary key to the table Employees on the field ID. Including more than one column name in the parentheses along with ID will create a Composite Primary Key. When adding more than one column, the column names must be separat...
The default position of an element is static. To quote MDN:
This keyword lets the element use the normal behavior, that is it is laid out in its current position in the flow. The top, right, bottom, left and z-index properties do not apply.
.element{
position:static;
}
This example limits SELECT result to 100 rows.
SELECT TOP 100 *
FROM table_name;
It is also possible to use a variable to specify the number of rows:
DECLARE @CountDesiredRows int = 100;
SELECT TOP (@CountDesiredRows) *
FROM table_name;
You can define implementation for specific instantiations of a template class/method.
For example if you have:
template <typename T>
T sqrt(T t) { /* Some generic implementation */ }
You can then write:
template<>
int sqrt<int>(int i) { /* Highly optimized integer implement...
$orderid = 12345;
$order = Mage::getModel('sales/order')->load($orderid);
The above code is roughly analogous to the following SQL query.
select * from sales_flat_order where entity_id=12345;
$incrementid = 100000000;
$order = Mage::getModel('sales/order')->loadByIncrementId($incrementid);
The above code is roughly analogous to the following SQL query.
select * from sales_flat_order where increment_id=100000000;
The increment_id is the customer facing order identifier, whereas...
Sort an enumeration in either ascending or descending order
Synonyms:
Sort-Object
sort
Assuming:
$names = @( "Aaron", "Aaron", "Bernie", "Charlie", "Danny" )
Ascending sort is the default:
$names | Sort-Object
$names | sort
Aaron
Aa...
You can group an enumeration based on an expression.
Synonyms:
Group-Object
group
Examples:
$names = @( "Aaron", "Albert", "Alphonse","Bernie", "Charlie", "Danny", "Ernie", "Frank")
$names | Group-Object -Prope...
Projecting an enumeration allows you to extract specific members of each object, to extract all the details, or to compute values for each object
Synonyms:
Select-Object
select
Selecting a subset of the properties:
$dir = dir "C:\MyFolder"
$dir | Select-Object Name, FullName, Att...
Class methods present alternate ways to build instances of classes. To illustrate, let's look at an example.
Let's suppose we have a relatively simple Person class:
class Person(object):
def __init__(self, first_name, last_name, age):
self.first_name = first_name
self.last...
There are two types of using keyword usage, using statement and using directive:
using statement:
The using keyword ensures that objects that implement the IDisposable interface are properly disposed after usage. There is a separate topic for the using statement
using directive
The using...
This is a very common Exception. It causes your application to stop during the start or execution of your app. In the LogCat you see the message:
android.content.ActivityNotFoundException : Unable to find explicit activity class;
have you declared this activity in your AndroidManifest.xml?
In ...
The cx and cy values designate the location of the center of the circle.
The r attribute specifies the size of the radius of the circle.
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<circle cx="40" cy="40&q...
class Car {
public position: number = 0;
private speed: number = 42;
move() {
this.position += this.speed;
}
}
In this example, we declare a simple class Car. The class has three members: a private property speed, a public property position and a public met...
class Car {
public position: number = 0;
protected speed: number = 42;
move() {
this.position += this.speed;
}
}
class SelfDrivingCar extends Car {
move() {
// start moving around :-)
super.move();
super.move();
}
}
...
In this example we use the constructor to declare a public property position and a protected property speed in the base class. These properties are called Parameter properties. They let us declare a constructor parameter and a member in one place.
One of the best things in TypeScript, is automatic ...
