Write a program which finds sum of natural numbers in Python.
To understand sum of natural numbers in Python, first understand natural numbers.
Set of natural numbers are denoted by N and it is positive whole numbers without having element zero i.e N={1, 2, 3, 4, 5, 6,………..}.
In this program I will add first four elements of natural numbers i.e sum=1+2+3+4 that would be equal to 10.
sum=0
i=1
while i <=4:
sum=sum+i
i=i+1
print(sum)
If you see the code first line is sum=0, it means sum refers value 0.
Second line is i=1 it means i refers value 1.
Third line is while loop which is a compound statement which checks whether i less than 4. If i is less than 4 control will enter inside while loop and executes two statements.
sum=sum+i
i=i+1
Further, to make you understand while loop very well, I have made a table in which columns are variables and expression and rows are updated values of variables.
To understand very clearly see the video below.