Pass by Value and Pass by Reference in Python

Passing a value and passing a reference explained below. Below is the simple example which shows how to use these in python.

What is Pass by value

What is pass by value? Passing a value as an argument to the function. The pass-by-value concept explained in three steps.

• Create a function
• pass value as an argument to the function
• to verify the result

A literal (20) as an argument supplied here. So it is called pass-by-value.

def my_pass_by_value(b):
    b += 2
    print(b)
c=my_pass_by_value(20)
print(c)
The result:
22
None
** Process exited - Return Code: 0 **
Press Enter to exit terminal

What is Pass by reference

Supplying a reference instead of value is called pass-by-refefence. The working principle you can see in the below example.

• Create a function
• pass reference as an argument to the function
• to verify the result

The below example tells how pass-by-reference works. Value not supplied, instead of the value provided a variable (reference).

def my_pass_by_reference(r):
    r += 10
    print(r)
ref1=100
h=my_pass_by_reference(ref1)
print(h)
The result
110
None
** Process exited - Return Code: 0 **
Press Enter to exit terminal

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