C # basic (5) enumeration, array, and namespace

1. Enumeration

Enumeration is a user-defined Integer type. When declaring an enumeration type, you must specify a group of acceptable instance values that can be included in the enumeration.

=, Gread =, fatherAge =}

Let's look at another example:

=

Output gread. Enumeration will be instantiated in the background as a structure derived from System. Enum, which means you can call methods and perform some operations on it.

2. Array

Declaration method:

Int [] userCount; // int [] indicates an integer array.

Int [] userConut = new int [20]; // declares an integer array of 20.

Note that all arrays are of reference type.

3. namespace

Call the classes in the namespace:

Namespace. class name such as google.com. MyFirstClass

Alias the namespace: using google = google.com

The first question before each class is using System; this is because many classes in C # r are included in the System namespace.