9.7 Local and External Parameter Names
When the preceding example functions were declared, they were configured with parameters that were assigned names which, in turn, could be referenced within the body of the function code. When declared in this way, these names are referred to as local parameter names.
In addition to local names, function parameters may also have external parameter names. These are the names by which the parameter is referenced when the function is called. By default, function parameters are assigned the same local and external parameter names. Consider, for example, the previous call to the buildMessageFor method:
let message = buildMessageFor(name: "John", count: 100)
As declared, the function uses “name” and “count” as both the local and external parameter names.
The default external parameter names assigned to parameters may be removed by preceding the local parameter names with an underscore (_) character as...
