If you’ve ever struggled with solving problems using recursion, or if you have to brush up your skills for an interview, this course is for you.

We'll start with the basics of what recursion is and why it’s important before diving into practicing solving actual questions. You’ll have access to detailed explanations and visualizations for each problem to help you along the way. 

By the time you have completed this course, you’ll be able to use all the concepts to solve complex real-world problems. We hope that through practicing recursion, you will be able to ace all recursion related questions in interviews at top tech companies.

Solving Problems with Recursion in Python

# Problem Statement
Implement a function that takes a variable `testVariable` containing a **string of digits** and prints all the sum of those digits.

## Input
A variable `testVariable` containing a string of digits.

## Output
Sum of the digits in the string

## Sample Input
```
"345"
```

## Sample Output
```
12
```

## Try it Yourself
Try to attempt this challenge by yourself before moving on to the solution. Good luck!




def sumDigits(testVariable):
  # Write your code here
  return None

def sumDigits(testVariable):
  if testVariable == "":
    return 0

  else:
    return int(testVariable[0]) + sumDigits(testVariable[1:])

---
In the next lesson, we have the solution review of this problem.

Given a string containing numbers, calculate the sum of those numbers. 

Recursion Fundamentals

Iteration Vs. Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Challenge 2: Sum of Digits in a String

Problem Statement

Input

Output

Sample Input

Sample Output

Try it Yourself