example program on constructors

Constructor:

class emp:

##constructor

    def __init__(self,name,id,sal):

        self.id=id

        self.name=name

        self.sal=sal

## defining the method      

    def display(self):

        print("empid:%d\n ename:%s\nsalary:%f"%(self.id,self.name,self.sal))

e1=emp("ravi",10,1500)

e2=emp("sita",20,2500)

e1.display()

e2.display()

"""output:

empid:10

 ename:ravi

salary:1500.000000

empid:20

 ename:sita

salary:2500.000000"""

  It is a special method, it is called automatically as soon as the object is created. Constructor are used to initialise the data into the object.

No need to call the constructors, once object the object is created, it is called automatically.

There are two types of constructors:

1.   Parameterised constructor

2.   Non-parameterised constructor

  Parameterised constructor: if atleast one parameter is there is called parameterised constructor.

Ex:

def __init__(self,id,name,sal):

….

Ex: E1=emp(10,’sita’,1500)

Non-parameterised constructor:

If there is no parameter in the constructor then it is called non-parameterised constructor. Except ‘self’ keyword.

Ex:

def __init__(self):

….

e.display()

Related Video: https://youtu.be/cm7EW6q-tR0
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