blocks|key|106830|text|完成此操作的最简单方法是在阵列上使用filter。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|106831|let+result+=+elements.filter+{+$0==5+}|code-block|syntax|javascript|106832|如果找到的元素存在，则result将具有该元素；如果该元素不存在，则该元素将为空。因此，只需检查result是否为空，就可以知道该元素是否存在于数组中。我将使用以下内容：|offset|length|style|CODE|106833|if+result.isEmpty+{
++++//+element+does+not+exist+in+array
}+else+{
++++//+element+exists
}|106834|entityMap^0|0|0|B|6|1C|6|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

<p>The simplest way to accomplish this is to use filter on the array.</p>

<pre><code>let result = elements.filter { $0==5 }
</code></pre>

<p><code>result</code> will have the found element if it exists and will be empty if the element does not exist. So simply checking if <code>result</code> is empty will tell you whether the element exists in the array. I would use the following:</p>

<pre><code>if result.isEmpty {
    // element does not exist in array
} else {
    // element exists
}
</code></pre>


blocks|key|107062|text|包含等于的属性的数组|type|unstyled|depth|inlineStyleRanges|entityRanges|data|107063|yourArray.contains(where:+{$0.propertyToCheck+==+value+})|code-block|syntax|javascript|107064|返回布尔值。|107065|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>An array that contains a property that equals to</p>
<pre><code>yourArray.contains(where: {$0.propertyToCheck == value })
</code></pre>
<p>Returns boolean.</p>


blocks|key|106865|text|从Swift+2.1开始，NSArrays的containsObject可以像这样使用：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|106866|if+myArray.containsObject(objectImCheckingFor){
++++//myArray+has+the+objectImCheckingFor
}|code-block|syntax|javascript|106867|entityMap^0|M|E|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<p>As of Swift 2.1 NSArrays have <code>containsObject</code>that can be used like so:</p>

<pre><code>if myArray.containsObject(objectImCheckingFor){
    //myArray has the objectImCheckingFor
}
</code></pre>


blocks|key|107041|text|数组|type|unstyled|depth|inlineStyleRanges|entityRanges|data|107042|let+elements+=+[1,+2,+3,+4,+5,+5]|code-block|syntax|javascript|107043|检查元素是否存在|107044|elements.contains(5)+//+true|107045|获取元素索引|107046|elements.firstIndex(of:+5)+//+4
elements.firstIndex(of:+10)+//+nil|107047|获取元素计数|107048|let+results+=+elements.filter+{+element+in+element+==+5+}
results.count+//+2|107049|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

<h3>Array</h3>
<pre><code>let elements = [1, 2, 3, 4, 5, 5]
</code></pre>
<h3>Check elements presence</h3>
<pre><code>elements.contains(5) // true
</code></pre>
<h3>Get elements index</h3>
<pre><code>elements.firstIndex(of: 5) // 4
elements.firstIndex(of: 10) // nil
</code></pre>
<h3>Get element count</h3>
<pre><code>let results = elements.filter { element in element == 5 }
results.count // 2
</code></pre>


blocks|key|106776|text|以防有人试图查找某个函数是否在所选函数中(如在UICollectionView或UITableView+cellForItemAtIndexPath函数中)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|106777|++++var+isSelectedItem+=+false
++++if+let+selectedIndexPaths+=+collectionView.indexPathsForSelectedItems()+as?+[NSIndexPath]{
++++++++if+contains(selectedIndexPaths,+indexPath)+{
++++++++++++isSelectedItem+=+true
++++++++}
++++}|code-block|syntax|javascript|106778|entityMap^0|N|G|14|B|1G|M|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|L|$]]

<p>Just in case anybody is trying to find if an <code>indexPath</code> is among the selected ones (like in a <code>UICollectionView</code> or <code>UITableView</code> <code>cellForItemAtIndexPath</code> functions):    </p>

<pre><code>    var isSelectedItem = false
    if let selectedIndexPaths = collectionView.indexPathsForSelectedItems() as? [NSIndexPath]{
        if contains(selectedIndexPaths, indexPath) {
            isSelectedItem = true
        }
    }
</code></pre>


blocks|key|4613510|text|如果用户找到特定的数组元素，则使用与整数值相同的以下代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4613511|var+arrelemnts+=+["sachin",+"test",+"test1",+"test3"]

+if+arrelemnts.contains("test"){
++++print("found")+++}else{
++++print("not+found")+++}|code-block|syntax|javascript|4613512|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>if user find particular array elements  then use below  code same as integer value.</p>

<pre><code>var arrelemnts = ["sachin", "test", "test1", "test3"]

 if arrelemnts.contains("test"){
    print("found")   }else{
    print("not found")   }
</code></pre>


blocks|key|4613566|text|斯威夫特|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4613567|如果你没有使用object，那么你可以使用这个代码来包含。|4613568|let+elements+=+[+10,+20,+30,+40,+50]

if+elements.contains(50)+{

+++print("true")

}|code-block|syntax|javascript|4613569|如果您在swift中使用NSObject类。这个变量是根据我的要求而定的。您可以根据自己的需求进行修改。|4613570|var+cliectScreenList+=+[ATModelLeadInfo]()
var+cliectScreenSelectedObject:+ATModelLeadInfo!|4613571|这是针对同一数据类型的。|4613572|{+$0.user_id+==+cliectScreenSelectedObject.user_id+}|4613573|如果您想要AnyObject类型。|4613574|{+"\($0.user_id)"+==+"\(cliectScreenSelectedObject.user_id)"+}|4613575|满条件|4613576|if+cliectScreenSelected.contains(+{+$0.user_id+==+cliectScreenSelectedObject.user_id+}+)+==+false+{

++++cliectScreenSelected.append(cliectScreenSelectedObject)

++++print("Object+Added")

}+else+{

++++print("Object+already+exists")

+}|4613577|entityMap^0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|15|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|16|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|17|8|@]|9|@]|A|$]]|$1|S|3|T|5|F|7|18|8|@]|9|@]|A|$G|H]]|$1|U|3|V|5|6|7|19|8|@]|9|@]|A|$]]|$1|W|3|X|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|Y|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|Z|$]]

<p>Swift  </p>

<p>If you are not using object then you can user this code for contains.</p>

<pre><code>let elements = [ 10, 20, 30, 40, 50]

if elements.contains(50) {

   print("true")

}
</code></pre>

<p>If you are using NSObject Class in swift. This variables is according to my requirement. you can modify for your requirement. </p>

<pre><code>var cliectScreenList = [ATModelLeadInfo]()
var cliectScreenSelectedObject: ATModelLeadInfo!
</code></pre>

<p>This is for a same data type.</p>

<pre><code>{ $0.user_id == cliectScreenSelectedObject.user_id }
</code></pre>

<p>If you want to AnyObject type.</p>

<pre><code>{ "\($0.user_id)" == "\(cliectScreenSelectedObject.user_id)" }
</code></pre>

<p>Full condition </p>

<pre><code>if cliectScreenSelected.contains( { $0.user_id == cliectScreenSelectedObject.user_id } ) == false {

    cliectScreenSelected.append(cliectScreenSelectedObject)

    print("Object Added")

} else {

    print("Object already exists")

 }
</code></pre>


blocks|key|4613618|text|对作业使用哈希表怎么样，像这样？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4613619|首先，创建一个"hash+map“泛型函数，扩展序列协议。|4613620|extension+Sequence+where+Element:+Hashable+{

++++func+hashMap()+->+[Element:+Int]+{
++++++++var+dict:+[Element:+Int]+=+[:]
++++++++for+(i,+value)+in+self.enumerated()+{
++++++++++++dict[value]+=+i
++++++++}
++++++++return+dict
++++}
}|code-block|syntax|javascript|4613621|只要数组中的项符合Hashable，这个扩展就会起作用，比如整数或字符串，下面是用法...|4613622|let+numbers+=+Array(0...50)+
let+hashMappedNumbers+=+numbers.hashMap()

let+numToDetect+=+35

let+indexOfnumToDetect+=+hashMappedNumbers[numToDetect]+//+returns+the+index+of+the+item+and+if+all+the+elements+in+the+array+are+different,+it+will+work+to+get+the+index+of+the+object!

print(indexOfnumToDetect)+//+prints+35|4613623|但是现在，让我们只关注元素是否在数组中。|4613624|let+numExists+=+indexOfnumToDetect+!=+nil+//+if+the+key+does+not+exist+
means+the+number+is+not+contained+in+the+collection.

print(numExists)+//+prints+true|4613625|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

<p>what about using a hash table for the job, like this?</p>

<p>first, creating a "hash map" generic function, extending the Sequence protocol.</p>

<pre><code>extension Sequence where Element: Hashable {

    func hashMap() -&gt; [Element: Int] {
        var dict: [Element: Int] = [:]
        for (i, value) in self.enumerated() {
            dict[value] = i
        }
        return dict
    }
}
</code></pre>

<p>This extension will work as long as the items in the array conform to Hashable, like integers or strings, here is the usage...</p>

<pre><code>let numbers = Array(0...50) 
let hashMappedNumbers = numbers.hashMap()

let numToDetect = 35

let indexOfnumToDetect = hashMappedNumbers[numToDetect] // returns the index of the item and if all the elements in the array are different, it will work to get the index of the object!

print(indexOfnumToDetect) // prints 35
</code></pre>

<p>But for now, let's just focus in check if the element is in the array.</p>

<pre><code>let numExists = indexOfnumToDetect != nil // if the key does not exist 
means the number is not contained in the collection.

print(numExists) // prints true
</code></pre>


<p>In Swift, how can I check if an element exists in an array? Xcode does not have any suggestions for <code>contain</code>, <code>include</code>, or <code>has</code>, and a quick search through the book turned up nothing. Any idea how to check for this? I know that there is a method <code>find</code> that returns the index number, but is there a method that returns a boolean like ruby's <code>#include?</code>?</p>

<p>Example of what I need:</p>

<pre><code>var elements = [1,2,3,4,5]
if elements.contains(5) {
  //do something
}
</code></pre>


How to check if an element is in an array

在Swift中，如何检查数组中是否存在元素？Xcode没有任何关于contain、include或has的建议，快速搜索一下这本书什么也没有找到。你知道怎么检查这个吗？我知道有一个返回索引号的方法find，但是有没有像ruby的#include?这样返回布尔值的方法呢我需要的示例：var elements = [1,2,3,4,5]if elements.contains(5) {  //do s

问如何检查元素是否在数组中
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