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

Answer 1

 func foo(bar:Any) -> Int {
        let a = 20
        if bar is Bar {
            let c = bar as? Bar
            return c!.a
        }
        return a
  }

Answer 2

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 3

Use the self keyword:

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