Object-oriented programming (OOP), which is an adopted programming paradigm, highly emphasizes the utilization of objects for data representation and manipulation. A notable characteristic of OOP is its ability to create methods that facilitate communication with these objects. In Python, there are three categories of methods; class methods, static methods, and instance methods.
In this article, we will see the difference between class method, static method, and instance method, along with the examples. So, let's get started!
What are Instance Methods?
In object-oriented programming (OOP) an instance method refers to a method that's specific to an object rather than the entire class. It carries out a series of actions on the data or value provided by the object variable. When we utilize the instance variable within these methods, they are referred to as instance methods. These methods have the ability to modify the state of the object. To interact with an instance method, we use the "self" keyword as the parameter, which points to the object.
Example 1
Code
Python
Python
class Student: # constructor def __init__(self, name, subject, percentage):
# Create an instance of the Student class obj = Student('Justin', 'Science', 85.5) obj.display()
Output:
Explanation
In the above code, the constructor is defined that creates the instance variable using the Python object. The method display() then accesses and shows these instance variables using the self keyword. Now, we will access and modify the instance variables in the code below.
Example 2
Code
Python
Python
class Student: # constructor def __init__(self, name, subject, percentage):
# Change the subject and percentage using the instance method new_subject = "Maths" new_percentage = 90.0 obj.change_subject_and_percentage(new_subject, new_percentage)
Based on the given example, it is evident that we successfully accessed the instance variable and made changes to its value. Subsequently, when the show() function was executed, it displayed the updated values.
What are Class Methods?
The class method is the method that is specific to the class instead of specific to the Instance. It can change the class state, which means it can modify class configuration globally. Class methods can only access the class variable. This method is used to create the factory method.
The syntax of Class methods is different; rather than taking self parameter, they accept cls as a parameter that points to the class. It cannot change the instance state. However, the changes made by the class method affect all instances of the class. The classmethod() or @classmethod decorator defines the class methods.
Code
Python
Python
class Student: # class variable Fee = 75000
def __init__(self, name, department): # Instance variable self.name = name self.department = department # instance method to access instance variable
In the above code, we defined the class variable name Fee and the method Updated_fee(). The Updated_fee() function accessed the class variable Fee and used this function to modify the Fee for all the students. We have also used two functions for printing, show() and show1(), for better understanding.
What are Static Methods?
A static method is a kind of method found in a class that doesn't have access, to the class ('cls') or instance ('self') parameters. It operates on its own. Doesn't rely on any attributes or behaviors of instances or classes. To define methods, we use either the @staticmethod decorator or the staticmethod() function. While these methods are related to a class's utility functions, they function independently. Cannot alter the behavior of the class or its instances.
Example
Code
Python
Python
class Student: @staticmethod def sample_method(name): return len(name)
# Get the student's name from the user name = input("Enter the student's name: ")
# Call the static method to count characters name_length = Student.sample_method(name)
# Display the result print(f"The name '{name}' has {name_length} characters.")
Output:
Explanation
In the above code, we have created a static method named sample_method(), which takes a student's name as a parameter and returns the number of characters in the name. The above code shows how the static method can be used to count the characters in names when called directly on the class and also when using an instance.
Note: In our compiler, give input of the name in the custom input section; otherwise, the code will not run properly.
Difference Between Class Method, Static Method, and Instance Method-Table
Aspect
Class Method
Instance Method
Static Method
Keyword/Decorator
‘@classmethod’
No keyword or decorator needed
‘staticmethod()’ or ‘@staticmethod’
Access to
Class-level data, not instance-specific data
Both instance-specific and class-level data
Neither instance-specific nor class-level data
First parameter
'cls' (class itself)
‘Self’ (instance)
Neither ‘cls’ nor ‘self’
Accessed through
Class name
Instance of the class
Instance of the class or Class name
Use case
When operation involves class-level data
When operation involves instance-specific data
When the utility function does not depend on instance/ class
What is the difference between an instance method and a class method?
An instance method is created from a specific object. For running an instance method, an object should be present in memory. In contrast, a class method does not require a specific instance.
What is a static method?
A method that belongs to a class instead of an instance of a class is known as a static method. Static methods are sometimes also known as class methods.
What is an instance method?
These are the methods that needs an object of its class to be created before it can be called.
What are the two types of instance methods?
The two types of instance methods are the Accessor Method(Getters) and the Mutator Method (Setter).
Conclusion
In this article, we discussed the Difference Between Class Method, Static Method, and Instance Method. We have seen what the Class, Static, and instance methods are, along with their examples, and then we saw the difference between them in the form of a table. We hope this blog has helped you enhance your knowledge of the difference Between Class Method, Static Method, and Instance Method. If you want to learn more, then check out our articles:
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