In Object-Oriented Programming (OOP), variables inside a class are mainly of two types:<\/p>\n\n\n\n
Understanding the difference is very important for writing clean and structured programs.<\/p>\n\n\n\n
Instance variables belong to a specific object.
Each object has its own separate copy of instance variables.<\/p>\n\n\n\n
They are usually defined inside the constructor using Output:<\/p>\n\n\n\n Here:<\/p>\n\n\n\n Class variables belong to the class itself, not to individual objects. They are defined inside the class but outside the constructor.<\/p>\n\n\n\n Output:<\/p>\n\n\n\n Both objects share the same Now both objects will show the updated value.<\/p>\n\n\n\n Instance Variable Class Variable Use Instance Variables when:<\/p>\n\n\n\n Use Class Variables when:<\/p>\n\n\n\n Instance variables store object-specific data. Both are essential for writing efficient and well-structured OOP programs.<\/p>\n\n\n\n <\/p> <\/div> <\/div>\n\n\nself<\/code>.<\/p>\n\n\n\nExample<\/strong><\/h3>\n\n\n\n
class Student:
def __init__(self, name):
self.name = name # Instance variables1 = Student(\"Hira\")
s2 = Student(\"Ali\")print(s1.name)
print(s2.name)<\/pre>\n\n\n\nHira
Ali<\/pre>\n\n\n\n\n
s1<\/code> and s2<\/code> have their own separate name<\/code><\/li>\n\n\n\nKey Points<\/strong><\/h3>\n\n\n\n
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self<\/code><\/li>\n\n\n\n2. Class Variables<\/strong><\/h2>\n\n\n\n
All objects share the same class variable.<\/p>\n\n\n\nExample<\/strong><\/h3>\n\n\n\n
class Student:
school = \"GIGZ Academy\" # Class variable def __init__(self, name):
self.name = names1 = Student(\"Hira\")
s2 = Student(\"Ali\")print(s1.school)
print(s2.school)<\/pre>\n\n\n\nGIGZ Academy
GIGZ Academy<\/pre>\n\n\n\nschool<\/code> value.<\/p>\n\n\n\nChanging Class Variable<\/strong><\/h3>\n\n\n\n
Student.school = \"W3Skillset\"print(s1.school)
print(s2.school)<\/pre>\n\n\n\nDifference Between Instance and Class Variables<\/strong><\/h2>\n\n\n\n
Belongs to object
Separate copy for each object
Defined using self<\/code>
Created when object is created<\/p>\n\n\n\n
Belongs to class
Shared by all objects
Defined directly inside class
Created when class is defined<\/p>\n\n\n\nWhen to Use Which?<\/strong><\/h2>\n\n\n\n
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Final Understanding<\/strong><\/h2>\n\n\n\n
Class variables store shared data for all objects of the class.<\/p>\n\n\n\n