Learn

Functions

Parameters and Arguments

Let’s take another look at the definition of the function `square`

from the previous exercise:

`def square(n):`

Here, `n`

is a *parameter* of `square`

. A parameter is a variable that is an input to a function. It says, “Later, when `square`

is used, you’ll be able to input any value you want, but for now we’ll call that future value n.” A function can have any number of parameters.

The values of the parameters passed into a function are known as the *arguments*. Recall in the previous example, we called:
```
py
square(10)
```

Here, the function `square`

was called with the parameter `n`

set to the argument `10`

.

Typically, when you call a function, you should pass in the same number of arguments as there are parameters.

To summarize:

- When defining a function, placeholder variables are called parameters.
- When using, or calling, a function, inputs into the function are called arguments.

Check out the function in the editor, `power`

. It should take two arguments, a base and an exponent, and raise the first to the power of the second. It’s currently broken, however, because its parameters are missing.

Replace the `___`

s with the parameters `base`

and `exponent`

and then call the `power`

function with a `base`

of `37`

and an `exponent`

of `4`

.