Open Radar

 
Summary: The code example for optional chaining in the Swift optional documentation https://developer.apple.com/documentation/swift/optional has a mistake, printing the wrong conclusion.

The example writes the following: 

    if let isPNG = imagePaths["star"]?.hasSuffix(".png") {
        print("The star image is in PNG format")
    }
    // Prints "The star image is in PNG format"

The code above however cannot state anything about the format of the path, only whether the path is nil or not.

Steps to Reproduce:
Put the following code in a Playground project:

    var imagePaths = ["star": "star"]

    if let isPNG = imagePaths["star"]?.hasSuffix(".png") {
        print("The star image is in PNG format")
    }

Expected Results:
Don't print anything, since the path does not have the .png suffix

Actual Results:
Prints "The star image is in PNG format"


Notes: To correct the code you could add ", isPNG" to the condition, like this:

    if let isPNG = imagePaths["star"]?.hasSuffix(".png"), isPNG {
        print("The star image is in PNG format")
    }