SOLVED: Multiple different behaviour after .reverse() or .reversed()

@jmgawecki

Apr '21

Hey guys, have a look at this code:

lets say that linesArray = ["A", "B", "C"] of type [String]

var linesArray      = fileContent.components(separatedBy: "\n")
        linesArray.reverse()
        // will print ["C", "B", "A"]. Is of type [String]
        let linesReverse = linesArray.reverse()
        // will print nothing. Is of type ()
        let linesReversed = linesArray.reversed()
        // will not flip, will print ["A", "B", "C"]. Is of type ReversedCollection<String>
        let linesReversedS :[String] = linesArray.reversed()
        // will flip, will print ["C", "B", "A"]. Is of type [String]

Why these results differ from each other so much? Thank you.

@NigelGee HWS+

Apr '21

.reverse() this take the array already there and reserve it where let linesReverse = linesArray.reverse() is trying to add a new property to the so you should use .reversed() and you need to cast the property to [String] so it will know to put the ReversedCollection<Array<String>>(_base: ["A", "B", "C"]).

You will find the same with shuffle() and shuffled()

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