JuniorTheoryCommon

What happens when this program is compiled and run?

SWIFT

func double(n: Int) -> Int {
    n * 2
}
print(double(4), terminator: " ")
print(double(n: 3))

It does not compile

Expecting 8 6: treating a label as optional when there is one argument. A parameter declared without _ needs its label in every call, so double(4) does not compile.
Expecting the error only when the program reaches double(4). Labels are checked by the compiler before the program runs, so nothing is printed at all.

JuniorTheoryCommon

SWIFT

func double(n: Int) -> Int {
    n * 2
}
print(double(4), terminator: " ")
print(double(n: 3))

It does not compile

Expecting 8 6: treating a label as optional when there is one argument. A parameter declared without _ needs its label in every call, so double(4) does not compile.
Expecting the error only when the program reaches double(4). Labels are checked by the compiler before the program runs, so nothing is printed at all.