Final answer:
If functions only printed values instead of returning them, it would inhibit their reusability and modularity, making it impossible to use their outputs in further operations. Returning values is fundamental to writing clean, maintainable code and is essential for function composition in programming.
Step-by-step explanation:
If functions in programming languages only printed output instead of returning values, it would limit their reusability and modularity. When a function prints the result, it just shows the value to the user and does not allow the program to use that value in further operations or in other parts of the program. If a function returns a value, it can be stored, further manipulated, or passed to other functions, making the code more efficient and versatile.
For instance, consider a function that calculates the sum of two numbers. If this function prints the result instead of returning it, you cannot use the sum in any further calculations within your program. However, if the function returns the sum, you can use the result in subsequent code—such as additional calculations or logical decisions. This is an essential concept in programming called function composition, where the output of one function becomes the input to another, enabling more complex operations and better organization of code.
Therefore, returning values from functions is a fundamental aspect of writing clean and maintainable code. It plays a crucial role in building scalable and complex systems and applications in programming.