In the previous article, we have discussed Python Program to Find Sum of Odd Numbers Using Recursion in a List/Array
Given a number and the task is to count the number of digits present in a given number using recursion in python.
Recursion:
Recursion is the process by which a function calls itself directly or indirectly, and the associated function is known as a recursive function. Certain issues can be addressed fairly easily using a recursive approach. Towers of Hanoi (TOH), Inorder /Preorder/Postorder Tree Traversals, DFS of Graph, and other analogous issues are examples.
Examples:
Example1:
Input:
Given Number = 567812
Output:
The Number of digits present in the above given Number { 567812 } = 6
Example2:
Input:
Given Number = 602
Output:
The Number of digits present in the above given Number { 602 } = 3
- Python Program to Find the Power of a Number Using Recursion
- Python Program to Reverse a String Using Recursion
- C Program to Find Sum of Digits of a Number using Recursion
Program to Count Number of Digits in a Number using Recursion in Python
Below are the ways to count the number of digits present in a given number using recursion in python:
Method #1: Using Recursion (Static Input)
Approach:
- Give the number as static input and store it in a variable.
- Take a variable say cnt_digits and initialize its value to 0.
- Pass the given number as an argument to the countnumbr_digits function.
- Create a recursive function to say countnumbr_digits which takes the given number as an argument and returns the count of the number of digits present in a given number.
- Make the cnt_digits a global declaration.
- Check if the given number is not equal to 0 using the if conditional statement.
- If the statement is true, then increment the value of cnt_digits by 1 and store it in the same variable.
- Pass the given number divided by 10 as an argument to the countnumbr_digits function(which removes the last digit of the number) {Recursive Logic}.
- Return cnt_digits.
- Print the count of the number of digits present in the above-given number.
- The Exit of the Program.
Below is the implementation:
# Create a recursive function to say countnumbr_digits which takes the given number as # an argument and returns the count of the number of digits present in a given number. def countnumbr_digits(gvn_numb): # Make the cnt_digits a global declaration. global cnt_digits # Check if the given number is not equal to 0 using the if conditional statement. if (gvn_numb != 0): # If the statement is true, then increment the value of cnt_digits by 1 and store it # inthe same variable. cnt_digits += 1 # Pass the given number divided by 10 as an argument to the countnumbr_digits function # (which removes the last digit of the number) {Recursive Logic}. countnumbr_digits(gvn_numb // 10) # Return cnt_digits. return cnt_digits # Give the number as static input and store it in a variable. gvn_numb = 567812 # Take a variable say cnt_digits and initialize its value to 0. # Pass the given number as an argument to the countnumbr_digits function. cnt_digits = 0 # Print the count of the number of digits present in the above-given number. print("The Number of digits present in the above given Number {", gvn_numb, "} = ", countnumbr_digits( gvn_numb))
Output:
The Number of digits present in the above given Number { 567812 } = 6
Method #2: Using Recursion (User Input)
Approach:
- Give the number as user input using the int(input()) function and store it in a variable.
- Take a variable say cnt_digits and initialize its value to 0.
- Pass the given number as an argument to the countnumbr_digits function.
- Create a recursive function to say countnumbr_digits which takes the given number as an argument and returns the count of the number of digits present in a given number.
- Make the cnt_digits a global declaration.
- Check if the given number is not equal to 0 using the if conditional statement.
- If the statement is true, then increment the value of cnt_digits by 1 and store it in the same variable.
- Pass the given number divided by 10 as an argument to the countnumbr_digits function(which removes the last digit of the number) {Recursive Logic}.
- Return cnt_digits.
- Print the count of the number of digits present in the above-given number.
- The Exit of the Program.
Below is the implementation:
# Create a recursive function to say countnumbr_digits which takes the given number as # an argument and returns the count of the number of digits present in a given number. def countnumbr_digits(gvn_numb): # Make the cnt_digits a global declaration. global cnt_digits # Check if the given number is not equal to 0 using the if conditional statement. if (gvn_numb != 0): # If the statement is true, then increment the value of cnt_digits by 1 and store it # inthe same variable. cnt_digits += 1 # Pass the given number divided by 10 as an argument to the countnumbr_digits function # (which removes the last digit of the number) {Recursive Logic}. countnumbr_digits(gvn_numb // 10) # Return cnt_digits. return cnt_digits # Give the number as user input using the int(input()) function and # store it in a variable. gvn_numb = int(input("Enter some random number = ")) # Take a variable say cnt_digits and initialize its value to 0. # Pass the given number as an argument to the countnumbr_digits function. cnt_digits = 0 # Print the count of the number of digits present in the above-given number. print("The Number of digits present in the above given Number {", gvn_numb, "} = ", countnumbr_digits( gvn_numb))
Output:
Enter some random number = 5341 The Number of digits present in the above given Number { 5341 } = 4
Find a comprehensive collection of Examples of Python Programs ranging from simple ones to complex ones to guide you throughout your coding journey.