In what cases should function parameters be specified in their declarations?

Function parameters should be specified in its declaration when the function needs to accept input data for processing. This allows:

• Passing different values when calling the function.
• Making the function universal and reusable.
• Improving code readability and understanding, as it shows what data the function needs.

If the function does not accept parameters, it is declared without them.

Example:

def greet(name):
    print(f"Hello, {name}!")

greet("Anna")  # Will output: Hello, Anna!

If parameters are not needed:

def say_hello():
    print("Hello!")

say_hello()