Create class: Class is followed by the name, where the first letter of the class name must be capitalized. When instantiated, it is instantiated with the new method. There are constructors in C #, and constructors have the same name as the class. In Ruby, the constructor is the Initialize method. When a class object is instantiated by the new method, the Initialize method is automatically invoked, passing the parameter in new to the Initialize method for initialization. A domain in C #, called an instance variable in Ruby, is preceded by an @ prefix, representing an instance variable.
Copy Code code as follows:
Class Customer
def initialize (name,age)
@name, @age =name,age
End
End
C1=customer.new ("Tom", 20)
Access Device
Instance variables can only be accessed through instance methods. If you want to access them, you can provide a method accessor. In C #, a property is defined as a method to represent a property in Java.
Copy Code code as follows:
Class Customer
def initialize (name,age)
@name, @age =name,age
End
def name
@name
End
def age
@age
End
End
The above two method x,y are defined, and they can read @x,@y instance variables. This defines the Read property method. If you want to do an assignment, you also define the Write property method:
Copy Code code as follows:
def name= (v)
@name =v
End
def age= (v)
@age =v
End
To be aware of:
Copy Code code as follows:
C1=customer.new ("Tom", 20)
C1.name= "Jhon"
Write properties can be used in this instance only in instances. If you are in a class, you cannot replace @name=value by Name=value. But you can use self to do this: Self.name=value
Ruby provides a simplified definition property method: Attr_reader and Attr_accessor. A read-write property with the same name is automatically created after the symbol.
Copy Code code as follows:
Class Customer
def initialize (name,age)
@name, @age =name,age
End
Attr_reader:name,:age
Attr_accessor:name,:age
End
C1=customer.new ("Tom", 20)
Puts C1.name,c1.age
C1.name= "Jhon"
C1.age=30
Puts C1.name,c1.age
class variables, constants, class methods
Class variables begin with @@ 开头 constants are accessed by [class name +:: constant name]; class method adds class name to the instance method method name. When you define a class method, you can use one of the following methods:
Copy Code code as follows:
Class<<self
Def method
End
End
So, this method is a class method:
Copy Code code as follows:
Class Customer
def initialize (name,age)
@name, @age =name,age
End
Class <<self
def showname
' OK '
End
End
End
Puts Customer.showname
the accessibility of the method
Public: Publicly available, by default the methods in the class are public and can be used anywhere. The construction method is initialize private.
Private: Proprietary, used internally by a class, can only be invoked by an instance method of a class or subclass. Can be called only implicitly through self, and cannot be displayed through an object. A private method M, which can only be invoked through M, and not by O.M or SELF.M.
Protected: A protected, internal or subclass-like method used within a class. The difference from private is that, in addition to self implicit invocation, the invocation can also be displayed through the class object.
You can declare the accessibility of a method in the following ways:
Copy Code code as follows:
#访问性 Private protected public
Private
def Private_method
Puts "Private method testing"
End
Protected
def Protected_method
Puts "protected method testing"
End
Public:protected_method
Factory method
Using the new method private, and then creating an instance from a class method
Copy Code code as follows:
Class Fruit
Private_class_method:new
def fruit.createfruit
New Fruit
End
End
F=fruit.createfruit
Modular Module
One of the
module functions is to be used as a name space. Calling a class is the same as calling a constant: two colons
Another effect is to be mixed. Include the instance methods in the module to the other classes. Sensory functions are introduced as namespaces in C #.
