I want to add a space between parameter names of a swift function. I want to achieve something like in the prepare for segue function provided by swift
func prepare(for segue: UIStoryboardSegue, sender: Any?)
That "for segue" parameter name that is used on the function call when you implement it.
Eg. I want to create a function func saveReceipt(for customer:....) then I want to call the function saveReceipt(for customer:....)
That is not how parameters work sadly.
Take the example of the prepareForSegue func. It looks like this as a func:
override prepare(for segue: ...) {
However, if you were to call it, it would look like this:
prepare(for: UIStoryboardSegue, ...)
You can only ever have one parameter name for when you call a func.
Edit
To look at your example, you could have a func like this:
func saveReceipt(for customer: ...) {
And then call it like this:
saveReceipt(for: MyCustomerClass, ...)
In your example for is the argument label whereas segue is the parameter name.
This "can allow a function to be called in an expressive, sentence-like manner, while still providing a function body that is readable and clear in intent."
(see https://docs.swift.org/swift-book/LanguageGuide/Functions.html)
That is, you use the argument label for the caller and the parameter name inside the function body.
In your second example your call saveReceipt using saveReceipt(for: myCustomer) (myCustomer is the variable holding your customer) and use customer as the parameter name inside the body.
prepare(for: ...).foris the argument label, which is used at the call site,segueis the parameter name, which is used internally inside the method.