Bottom-up approach is used by C.

The bottom-up approach is a programming methodology where the program development starts with the implementation of lower-level modules and gradually builds up to higher-level modules. In this approach, the focus is on developing individual components or functions and then integrating them to create a complete program.

Advantages of Bottom-up approach:
1. Modularization: The bottom-up approach promotes modularization, as it allows developers to focus on building smaller, manageable components first. This makes the development process more organized and easier to maintain.

2. Easy Debugging: As the program is developed in small modules, debugging becomes easier. If any errors or issues arise, they can be easily identified and resolved within the specific module, without affecting the entire program.

3. Reusability: Bottom-up approach encourages the development of reusable modules. Once a module is created and tested, it can be reused in multiple programs, saving time and effort in future projects.

4. Incremental Development: This approach allows for incremental development, where each module can be tested and validated independently before integration. This reduces the risk of errors and ensures a more reliable and robust final product.

Example of Bottom-up approach in C:
Let's consider a simple example where we need to create a program to calculate the average of three numbers.

1. First, we would start by creating a function to input three numbers.
2. Then, we would create a function to calculate the sum of three numbers.
3. Next, we would create a function to calculate the average by dividing the sum by 3.
4. Finally, we would integrate these functions and create a main function to execute the program.

In this example, we start with developing the lower-level modules (input function, sum function) and gradually build up to the higher-level module (average calculation). This follows the bottom-up approach as we focus on developing individual components and then integrate them to create the complete program.

Overall, the bottom-up approach is beneficial in terms of modularization, easy debugging, reusability, and incremental development. It allows for better organization and efficiency in program development.