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iOS

Posted by Zaq Dayton
Zaq Dayton
2,244 Points

I understand the difference between an external and internal parameter, but what's the point of an external one?

As stated, I understand the difference between the two. However, I can't think of a situation where I'd need to have a different external label when calling the function. Can someone give me an example of why I would need an external one? Nothing is coming up for me... Thanks!

Zaq Dayton
Zaq Dayton
2,244 Points

Well, correct me if I'm wrong, but I think I may have answered my own question. Hypothetically, if you have a two functions "calculateArea" and "calculateVolume", external parameter labels may help, because to calculate area you need "length" times "width", and to calculate volume you need "length" times "width" times "height". Therefore, if the internal parameters for each function were "length" and "height", then it may be confusing?

func calculateArea(length: Int, width: Int) -> Int {
        let area = length * width
}

func calculateVolume(length: Int, width: Int, height: Int) -> Int {
        let volume = length * width * height
}

calculateArea(23, width: 3)
calculateVolume(23, width: 3, height: 1)

So, you could use external parameter labeling as such to avoid confusion:

func calculateArea(areaLength length: Int, areaWidth width: Int) -> Int {
        let area = length * width
}

func calculateVolume(volumeLength length: Int, volumeWidth width: Int, volumeHeight height: Int) -> Int {
        let volume = length * width * height
}

calculateArea(areaLength: 23, areaWidth: 3)
calculateVolume(volumeLength: 23, volumeWidth: 3, volumeHeight: 1)

However, the function that you call gives the context, so I'm not sure why it would be super confusing in this scenario. Can anyone still give me another one, and am I on the right track? Thanks!