Components of a Function

Functions are mainly composed of Parameters, Arguments, and Return Values.

Parameters are variables used when defining a function to determine what kind of input the function will take.

For example, when defining a function that adds two numbers, the parameters are the two numbers to be added.

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def add_numbers(a, b):
    # Return the sum of a and b
    result = a + b

    # Return the result
    return result

In the code above, the add_numbers function takes two parameters, a and b, and returns the result of adding these two numbers.

Arguments are the actual values that you pass to the function when calling it.

For example, when calling add_numbers(3, 5), the numbers 3 and 5 are the arguments.

These values are then used within the function as the parameters a and b.

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def add_numbers(a, b):
    result = a + b
    return result

# Store the result of adding 3 and 5 in result
result = add_numbers(3, 5)

# Print 8
print(result)

In the previous function example, the add_numbers function returned the result of adding two numbers in the result variable.

Here, the return keyword is used to return the final result of the function.

A function with a return value sends that value back to where the function was called.

For example, a function to convert a given temperature from Celsius (C) to Fahrenheit (F) can be defined as follows:

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# Function to convert input Celsius temperature to Fahrenheit
def celsius_to_fahrenheit(celsius):
    # Convert Celsius to Fahrenheit
    fahrenheit = celsius * 9 / 5 + 32

    # Return the Fahrenheit value
    return fahrenheit

# Convert 30 degrees Celsius to Fahrenheit
result = celsius_to_fahrenheit(30)

# Print 86
print(result)

The celsius_to_fahrenheit function takes the parameter celsius, which is a Celsius temperature, and returns the converted Fahrenheit value.

When calling celsius_to_fahrenheit(30), the result is that 30 degrees Celsius is converted to 86 degrees Fahrenheit.