1. Introduction

### Goal of the Tutorial
This tutorial aims at illuminating the similarities and differences between Black Box Testing and White Box Testing. By the end of this tutorial, you will have an understanding of when to use each method, their pros and cons, and how they are implemented in practice.

### Learning Outcomes
- Understand the concepts of Black Box and White Box Testing
- Identify the differences and similarities between the two
- Learn how to implement each method
- Understand when to use each method

### Prerequisites
Basic understanding of software development and testing is beneficial but not mandatory.

2. Step-by-Step Guide

### Black Box Testing
Black Box Testing involves testing software without knowledge of its internal workings. The tester provides inputs and checks the outputs without concerning themselves with how the software produces the results.

### White Box Testing
White Box Testing, on the other hand, involves testing software with full knowledge of its internal workings. The tester not only provides inputs and checks outputs but also validates the internal operations of the software.

### Key Differences
- Black Box Testing is primarily focused on validating external functionality, while White Box Testing validates both external functionality and internal logic.
- Black Box testing can be performed without any knowledge of programming, while White Box Testing requires a deep understanding of the codebase.
- Black Box Testing is usually performed by testers while White Box Testing is performed by developers or testers with a strong programming background.

3. Code Examples

Here are some practical examples of how each method might be implemented in practice.

### Black Box Testing
```python
# Function to test
def add(a, b):
return a + b

# Black Box Test
assert add(2, 2) == 4 # Passes
assert add(2, 3) == 5 # Passes
assert add(2, 2) == 5 # Fails
`` In the above Black Box Testing example, we only care about the output of the functionadd()for given inputs. We aren't concerned with howadd()` works internally.

### White Box Testing
```python
# Function to test
def add(a, b):
# Check if inputs are integers
assert type(a) == int, "a is not an integer"
assert type(b) == int, "b is not an integer"

   return a + b

# White Box Test
try:
add(2, "2") # Fails
except AssertionError as e:
print(e)

try:
add(2, 2) # Passes
except AssertionError as e:
print(e)
`` In the above White Box Testing example, we are validating the internal workings of the functionadd(). We check ifadd()` correctly handles non-integer inputs.

4. Summary

• Black Box Testing checks the functionality of software, while White Box Testing checks both functionality and internal structure.
• Black Box Testing doesn't require programming knowledge, while White Box Testing does.

### Next Steps
- Try implementing Black Box and White Box Testing in your projects.
- Learn about other testing methodologies like Grey Box Testing and Integration Testing.

### Additional Resources
- Software Testing Fundamentals
- The Art of Software Testing

5. Practice Exercises

### Exercise 1
Write Black Box Tests for a function that calculates the factorial of a number.

### Exercise 2
Write White Box Tests for a function that sorts a list of integers.

### Tips for Further Practice
- Try to write tests for more complex functions.
- Experiment with different types of inputs to fully test your functions.