Hey guys, in this blog we will see a Python Program to Reverse a Number.
Example 1: Reverse a Number using a while loop
num = int(input('Enter a number -> '))
reversed_num = 0
while num != 0:
digit = num % 10
reversed_num = reversed_num * 10 + digit
num //= 10
print("Reversed Number: " + str(reversed_num))
Output
Enter a number -> 7042 Reversed Number: 2407
- This is the most commonly used algorithm for reversing a number.
- In this, we keep on extracting the last number from our main number and keep on adding it to our reversed number.
- The flow is something like the below:
curr = 7042 ; digit = 0 ; reverse = 0
curr = 704 ; digit = 2 ; reverse = 0 x 10 + 2 = 2
curr = 70 ; digit = 4 ; reverse = 2 x 10 + 4 = 24
curr = 7 ; digit = 0 ; reverse = 24 x 10 + 0 = 240
curr = 0 ; digit = 7 ; reverse = 240 x 10 + 7 = 2407
Example 2: Using String slicing
num = int(input('Enter a number -> '))
print(str(num)[::-1])
Output
Enter a number -> 7042 2407
- Here we have reversed the number using string operations.
- First of all, we converted the number to a string and then reversed the string using [::-1].
Check out our other python programming examples…