What will happen if the return statement is omitted in a function?

When a return statement is omitted in a function, the function will automatically return None by default. In Python, all functions return a value. If there is no explicit return statement provided, Python includes a hidden return of None upon reaching the end of the function body. This behavior allows for functions to terminate and signals that no value was returned intentionally.

For instance, if a function is defined as follows:

def my_function():

print("Hello, world!")

When my_function() is called, it will print "Hello, world!" to the console, and upon completion, it will return None. This return value can be confirmed by using:

result = my_function()

print(result)  # This will print: None

This understanding is fundamental in Python programming as it clarifies how functions behave regarding output when no explicit return statement is provided.