func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
0
}
Why does compiler does not throw error even when return keyword is not added while returning built-in data types ?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
UITableViewCell()
}
Whereas in case of non built in types it throws error : Missing return in a function expected to return
Swift 5.1 added the ability to omit the return keyword for functions with a single-expression. See https://github.com/apple/swift-evolution/blob/master/proposals/0255-omit-return.md
It's got nothing to do with built-in data types vs. non-built-in; in fact I'm not even sure what you mean by that.
If you get the error it's because your function is no longer a single expression.
// This compiles
func foo() -> Int {
42
}
func bar() -> Int {
#warning("This won't compile")
42
}