在 Swift 中从数组中删除重复元素 [英] Removing duplicate elements from an array in Swift
本文介绍了在 Swift 中从数组中删除重复元素的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
I might have an array that looks like the following:
[1, 4, 2, 2, 6, 24, 15, 2, 60, 15, 6]
Or, really, any sequence of like-typed portions of data. What I want to do is ensure that there is only one of each identical element. For example, the above array would become:
[1, 4, 2, 6, 24, 15, 60]
Notice that the duplicates of 2, 6, and 15 were removed to ensure that there was only one of each identical element. Does Swift provide a way to do this easily, or will I have to do it myself?
解决方案
You can roll your own, e.g. like this:
func unique<S : Sequence, T : Hashable>(source: S) -> [T] where S.Iterator.Element == T {
var buffer = [T]()
var added = Set<T>()
for elem in source {
if !added.contains(elem) {
buffer.append(elem)
added.insert(elem)
}
}
return buffer
}
let vals = [1, 4, 2, 2, 6, 24, 15, 2, 60, 15, 6]
let uniqueVals = uniq(vals) // [1, 4, 2, 6, 24, 15, 60]
And as an extension for Array
:
extension Array where Element: Hashable {
func uniqued() -> Array {
var buffer = Array()
var added = Set<Element>()
for elem in self {
if !added.contains(elem) {
buffer.append(elem)
added.insert(elem)
}
}
return buffer
}
}
Or more elegantly (Swift 4/5):
extension Sequence where Element: Hashable {
func uniqued() -> [Element] {
var set = Set<Element>()
return filter { set.insert($0).inserted }
}
}
Which would be used:
[1,2,4,2,1].uniqued() // => [1,2,4]
这篇关于在 Swift 中从数组中删除重复元素的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文