blocks|key|18878|text|您只需使用以下命令即可创建一个包含给定Swift+Set中所有元素的数组|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|18879|let+array+=+Array(someSet)|code-block|syntax|javascript|18880|这是可行的，因为Set符合SequenceType协议，并且Array可以用序列进行初始化。示例：|18881|let+mySet+=+Set(["a",+"b",+"a"])++//+Set<String>
let+myArray+=+Array(mySet)++++++++//+Array<String>
print(myArray)+//+[b,+a]|18882|entityMap^0|P|3|0|0|8|3|D|C|U|5|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|P|$]]

You can create an array with all elements from a given Swift 
<code>Set</code> simply with

<pre><code>let array = Array(someSet)
</code></pre>

This works because <code>Set</code> conforms to the <code>SequenceType</code> protocol
and an <code>Array</code> can be initialized with a sequence. Example:

<pre><code>let mySet = Set(["a", "b", "a"]) // Set&lt;String&gt;
let myArray = Array(mySet) // Array&lt;String&gt;
print(myArray) // [b, a]
</code></pre>

blocks|key|18889|text|调用此方法并传递您的set|type|unstyled|depth|inlineStyleRanges|entityRanges|data|18890|func+getArrayFromSet(set:NSSet)->+NSArray+{

return+set.map+({+String($0)+})
}|code-block|syntax|javascript|18891|如下所示：|18892|var+letters:Set+=+Set<String>(arrayLiteral:+"test","test")+//+your+set
print(self.getArrayFromSet(letters))|18893|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

call this method and pass your set 

<pre><code>func getArrayFromSet(set:NSSet)-&gt; NSArray {

return set.map ({ String($0) })
}
</code></pre>

Like This :

<pre><code>var letters:Set = Set&lt;String&gt;(arrayLiteral: "test","test") // your set
print(self.getArrayFromSet(letters))
</code></pre>

blocks|key|18923|text|对于Swift+2.x和更高版本(来自Swift编程语言指南中的Collection+Types)，当前的答案似乎是迭代集合项目，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|18924|for+item+in+myItemSet+{
+++...
}|code-block|syntax|javascript|18925|或者，使用"sorted“方法：|18926|let+itemsArray+=+myItemSet.sorted()|18927|看来Swift的设计者不喜欢allObjects作为一种访问机制，因为集合并不是真正有序的，所以他们想确保你在没有应用显式排序的情况下不会得到一个数组。|18928|如果您不想要排序的开销，也不关心顺序，我通常使用map或flatMap方法，这应该会更快地提取数组：|18929|let+itemsArray+=+myItemSet.map+{+$0+}|18930|它将构建一个Set拥有的类型的数组，如果您需要它是一个特定类型的数组(例如，从一组未声明为类型化set的托管对象关系中获得权限)，您可以这样做：|18931|var+itemsArray+:+[MyObjectType]+=+[]
if+let+typedSet+=+myItemSet+as?+Set<MyObjectType>+{
+itemsArray+=+typedSet.map+{+$0+}
}|18932|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|11|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|12|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

The current answer for Swift 2.x and higher (from the Swift Programming Language guide on Collection Types) seems to be to either iterate over the Set entries like so:

<pre><code>for item in myItemSet {
 ...
}
</code></pre>

Or, to use the "sorted" method:

<pre><code>let itemsArray = myItemSet.sorted()
</code></pre>

It seems the Swift designers did not like allObjects as an access mechanism because Sets aren't really ordered, so they wanted to make sure you didn't get out an array without an explicit ordering applied.

If you don't want the overhead of sorting and don't care about the order, I usually use the map or flatMap methods which should be a bit quicker to extract an array:

<pre><code>let itemsArray = myItemSet.map { $0 }
</code></pre>

Which will build an array of the type the Set holds, if you need it to be an array of a specific type (say, entitles from a set of managed object relations that are not declared as a typed set) you can do something like:

<pre><code>var itemsArray : [MyObjectType] = []
if let typedSet = myItemSet as? Set&lt;MyObjectType&gt; {
 itemsArray = typedSet.map { $0 }
}
</code></pre>

An <code>NSSet</code> can be converted to <code>Array</code> using <code>set.allObjects()</code> but there is no such method in the new <code>Set</code> (introduced with Swift 1.2). It can still be done by converting Swift Set to NSSet and use the <code>allObjects()</code> method but that is not optimal.

Swift Set to Array

Swift

NSSet可以使用set.allObjects()转换为Array，但在新的Set (随Swift 1.2引入)中没有这种方法。这仍然可以通过将Swift集转换为NSSet并使用allObjects()方法来完成，但这并不是最优的。

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