Interview question

What are class methods and static methods? Class methods और static methods क्या हैं?

Answer

Type	Decorator	Receives	Use Case
Instance	@property	self	Instance data
Class Method	@classmethod	cls	Class data
Static Method	@staticmethod	None	Utility functions

class MyClass:
    class_var = 0
    
    def __init__(self, value):
        self.value = value
        MyClass.class_var += 1
    
    # Instance method
    def instance_method(self):
        return f'Value: {self.value}'
    
    # Class method
    @classmethod
    def from_string(cls, string):
        value = int(string)
        return cls(value)
    
    @classmethod
    def get_count(cls):
        return cls.class_var
    
    # Static method
    @staticmethod
    def is_positive(num):
        return num > 0
    
    @staticmethod
    def multiply(a, b):
        return a * b

# Using class method
obj = MyClass.from_string('10')
print(MyClass.get_count())  # 1

# Using static method
print(MyClass.is_positive(5))    # True
print(MyClass.multiply(3, 4))    # 12

# Static method - no access to self or cls
class Math:
    @staticmethod
    def add(a, b):
        return a + b
    
    @staticmethod
    def subtract(a, b):
        return a - b

print(Math.add(5, 3))      # 8
print(Math.subtract(5, 3))  # 2

# Instance method - self
def method(self):
    return self.value

# Class method - cls
@classmethod
def class_method(cls):
    return cls.class_var

# Static method - no self/cls
@staticmethod
def static_method(a, b):
    return a + b

Was this answer clear?

Subjects

Related questions