Question

How to remove duplicate elements from a list of strings in Swift

Answer 1

import Foundation

func removeDuplicates(elements: [String]) -> [String] {
    var encountered = Set<String>()
    
    return elements.filter { encountered.insert($0).inserted }
}

let elements = ["aaa", "bbb", "ccc", "ddd", "eee", "aaa", "www", "ddd", "bbb", "aaa"]

print(elements)
print(removeDuplicates(elements: elements))



/*
run:

["aaa", "bbb", "ccc", "ddd", "eee", "aaa", "www", "ddd", "bbb", "aaa"]
["aaa", "bbb", "ccc", "ddd", "eee", "www"]

*/

 

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Answer 2

import Foundation

func removeDuplicates(elements: [String]) -> [String] {
    var encountered = Set<String>()
    var result = [String]()

    for element in elements {
        if encountered.insert(element).inserted {
            result.append(element)
        }
    }

    return result
}

let elements = ["aaa", "bbb", "ccc", "ddd", "eee", "aaa", "www", "ddd", "bbb", "aaa"]

print(elements)
print(removeDuplicates(elements: elements)) 



/*
run:

["aaa", "bbb", "ccc", "ddd", "eee", "aaa", "www", "ddd", "bbb", "aaa"]
["aaa", "bbb", "ccc", "ddd", "eee", "www"]

*/

 

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