There are some cases in which we may not want to expose methods outside of the scope of the structure such as when the method might access or modify some sensitive data. For those cases, we can use the private keyword to define a private method, in the same way we defined a private property:

struct WizardCat {
    private func secretSpell() -> String {
        "Abracadabra"
    }
}

As we saw in the previous exercise, now only methods inside the scope of the structure can call secretSpell(). If we try to call the function outside of the scope of WizardCat we will encounter this error:

error: 'secretSpell' is inaccessible due to 'private' protection level