Accessing global variable in Swift

Question

Given this sample Swift code:

var a = 10;

func foo() -> Int {
    var a = 20;
    return a;
}

How can function foo get access to global variable a with value 10 instead of the local a with value 20?

Please note that both a and foo are not declared inside a class but in a generic module. I am looking for a way to tell Swift to access globally defined a var instead of the locally defined one.

Answer 1

I created a project in Xcode, a console application, the target is here a module. So I named the project test and the target has the same name so in the project the module itself has also the name test. Any global definition will be implicit a call to test. . Just like the global Swift functions are implicit a call to Swift., like Swift.print("...").

var a = 10;

func foo() -> Int {
    let a = 20;
    Swift.print(test.a) // same as print(test.a)

    return a;
}

test.foo() // same as foo()

Output is:

10

---

So you have to add the module name before the variable to get the global one and not the local one overshadowing it.

Answer 2

Use the self keyword:

func foo() -> Int {
    var a = 20;
    return self.a;
}