blocks|key|1524115|text|如果您的目标是iOS+5%2B+(涵盖整个iOS世界)，最好使用NSOrderedSet。它删除了重复项并保留了NSArray的顺序。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1524116|只管去做|1524117|NSOrderedSet+*orderedSet+=+[NSOrderedSet+orderedSetWithArray:yourArray];|code-block|syntax|javascript|1524118|现在可以将其转换回唯一的NSArray|1524119|NSArray+*uniqueArray+=+orderedSet.array;|1524120|或者直接使用orderedSet，因为它有和NSArray一样的方法，比如objectAtIndex:、firstObject等等。|1524121|在NSOrderedSet上使用contains进行成员资格检查比在NSArray上更快|1524122|有关更多信息，请查看NSOrderedSet+Reference|1524123|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/ios/#documentation/Foundation/Reference/NSOrderedSet_Class/Reference/Reference.html^0|U|C|1I|7|0|0|0|0|0|11|E|1G|B|0|1|C|G|8|Y|7|0|A|M|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|19|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1A|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1B|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1C|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1D|8|@$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|S|3|T|5|6|7|1I|8|@$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|U|3|V|5|6|7|1P|8|@]|D|@$9|1Q|A|1R|1|1S]]|E|$]]|$1|W|3|-4|5|6|7|1T|8|@]|D|@]|E|$]]]|X|$Y|$5|Z|10|11|E|$12|13]]]]

If you are targeting iOS 5+ (what covers the whole iOS world), best use <code>NSOrderedSet</code>. It removes duplicates and retains the order of your <code>NSArray</code>.

Just do

<pre><code>NSOrderedSet *orderedSet = [NSOrderedSet orderedSetWithArray:yourArray];
</code></pre>

You can now convert it back to a unique NSArray

<pre><code>NSArray *uniqueArray = orderedSet.array;
</code></pre>

Or just use the orderedSet because it has the same methods like an NSArray like <code>objectAtIndex:</code>, <code>firstObject</code> and so on.

A membership check with <code>contains</code> is even faster on the <code>NSOrderedSet</code> than it would be on an <code>NSArray</code>

For more checkout the <a href="https://developer.apple.com/library/ios/#documentation/Foundation/Reference/NSOrderedSet_Class/Reference/Reference.html">NSOrderedSet Reference</a>

blocks|key|1524053|text|在OS+X+v10.7及更高版本中可用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1524054|如果你担心订单，正确的方法是|1524055|NSArray+*no+=+[[NSOrderedSet+orderedSetWithArray:originalArray]allObjects];|code-block|syntax|javascript|1524056|下面是按顺序从NSArray中删除重复值的代码。|1524057|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Available in OS X v10.7 and later.

If you are worried about the order,right way to do 

<pre><code>NSArray *no = [[NSOrderedSet orderedSetWithArray:originalArray]allObjects];
</code></pre>

Here is the code of removing duplicates values from NSArray in Order.

blocks|key|1524309|text|需要订单|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1524310|NSArray+*yourarray+=+@[@"a",@"b",@"c"];
NSOrderedSet+*orderedSet+=+[NSOrderedSet+orderedSetWithArray:yourarray];
NSArray+*arrayWithoutDuplicates+=+[orderedSet+array];
NSLog(@"%25@",arrayWithoutDuplicates);|code-block|syntax|javascript|1524311|或者不需要命令|1524312|NSSet+*set+=+[NSSet+setWithArray:yourarray];
NSArray+*arrayWithoutOrder+=+[set+allObjects];
NSLog(@"%25@",arrayWithoutOrder);|1524313|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|$]]

need order 

<pre><code>NSArray *yourarray = @[@"a",@"b",@"c"];
NSOrderedSet *orderedSet = [NSOrderedSet orderedSetWithArray:yourarray];
NSArray *arrayWithoutDuplicates = [orderedSet array];
NSLog(@"%@",arrayWithoutDuplicates);
</code></pre>

or don't need order

<pre><code>NSSet *set = [NSSet setWithArray:yourarray];
NSArray *arrayWithoutOrder = [set allObjects];
NSLog(@"%@",arrayWithoutOrder);
</code></pre>

blocks|key|1524180|text|请注意，如果您有一个排序的数组，则不需要检查数组中的所有其他项，只需要检查最后一项。这应该比检查所有项目要快得多。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1524181|//+sortedSourceArray+is+the+source+array,+already+sorted
NSMutableArray+*newArray+=+[[NSMutableArray+alloc]+initWithObjects:[sortedSourceArray+objectAtIndex:0]];
for+(int+i+=+1;+i+<+[sortedSourceArray+count];+i%2B%2B)
{
++++if+(![[sortedSourceArray+objectAtIndex:i]+isEqualToString:[sortedSourceArray+objectAtIndex:(i-1)]])
++++{
++++++++[newArray+addObject:[tempArray+objectAtIndex:i]];
++++}
}|code-block|syntax|javascript|1524182|看起来同样建议的NSOrderedSet答案需要的代码要少得多，但是如果你由于某种原因不能使用NSOrderedSet，并且你有一个排序的数组，我相信我的解决方案将是最快的。我不确定它与NSOrderedSet解决方案的速度相比如何。还要注意的是，我的代码是用isEqualToString:检查的，因此同一系列字母不会在newArray中多次出现。我不确定NSOrderedSet解决方案是否会根据值或内存位置删除重复项。|offset|length|style|CODE|1524183|我的示例假设sortedSourceArray只包含NSStrings、NSMutableStrings或两者的混合。如果sortedSourceArray仅包含NSNumber%25s或仅包含NSDate%25s，则可以替换|1524184|if+(![[sortedSourceArray+objectAtIndex:i]+isEqualToString:[sortedSourceArray+objectAtIndex:(i-1)]])|1524185|使用|1524186|if+([[sortedSourceArray+objectAtIndex:i]+compare:[sortedSourceArray+objectAtIndex:(i-1)]]+!=+NSOrderedSame)|1524187|它应该能完美地工作。如果sortedSourceArray包含NSStrings、NSNumbers和/或NSDates的混合，它可能会崩溃。|1524188|entityMap^0|0|0|8|C|1B|C|2L|C|3M|G|4H|8|4Z|C|0|6|H|Q|8|10|F|1P|H|29|8|2N|6|0|0|0|0|C|H|V|8|15|8|1H|6|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@$I|11|J|12|K|L]|$I|13|J|14|K|L]|$I|15|J|16|K|L]|$I|17|J|18|K|L]|$I|19|J|1A|K|L]|$I|1B|J|1C|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|1D|8|@$I|1E|J|1F|K|L]|$I|1G|J|1H|K|L]|$I|1I|J|1J|K|L]|$I|1K|J|1L|K|L]|$I|1M|J|1N|K|L]|$I|1O|J|1P|K|L]]|9|@]|A|$]]|$1|O|3|P|5|D|7|1Q|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|1R|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|1S|8|@]|9|@]|A|$E|F]]|$1|U|3|V|5|6|7|1T|8|@$I|1U|J|1V|K|L]|$I|1W|J|1X|K|L]|$I|1Y|J|1Z|K|L]|$I|20|J|21|K|L]]|9|@]|A|$]]|$1|W|3|-4|5|6|7|22|8|@]|9|@]|A|$]]]|X|$]]

Note that if you have a sorted array, you don't need to check against every other item in the array, just the last item. This should be much faster than checking against all items.

<pre><code>// sortedSourceArray is the source array, already sorted
NSMutableArray *newArray = [[NSMutableArray alloc] initWithObjects:[sortedSourceArray objectAtIndex:0]];
for (int i = 1; i &lt; [sortedSourceArray count]; i++)
{
 if (![[sortedSourceArray objectAtIndex:i] isEqualToString:[sortedSourceArray objectAtIndex:(i-1)]])
 {
 [newArray addObject:[tempArray objectAtIndex:i]];
 }
}
</code></pre>

It looks like the <code>NSOrderedSet</code> answers that are also suggested require a lot less code, but if you can't use an <code>NSOrderedSet</code> for some reason, and you have a sorted array, I believe my solution would be the fastest. I'm not sure how it compares with the speed of the <code>NSOrderedSet</code> solutions. Also note that my code is checking with <code>isEqualToString:</code>, so the same series of letters will not appear more than once in <code>newArray</code>. I'm not sure if the <code>NSOrderedSet</code> solutions will remove duplicates based on value or based on memory location.

My example assumes <code>sortedSourceArray</code> contains just <code>NSString</code>s, just <code>NSMutableString</code>s, or a mix of the two. If <code>sortedSourceArray</code> instead contains just <code>NSNumber</code>s or just <code>NSDate</code>s, you can replace 

<pre><code>if (![[sortedSourceArray objectAtIndex:i] isEqualToString:[sortedSourceArray objectAtIndex:(i-1)]])
</code></pre>

with 

<pre><code>if ([[sortedSourceArray objectAtIndex:i] compare:[sortedSourceArray objectAtIndex:(i-1)]] != NSOrderedSame)
</code></pre>

and it should work perfectly. If <code>sortedSourceArray</code> contains a mix of <code>NSString</code>s, <code>NSNumber</code>s, and/or <code>NSDate</code>s, it will probably crash.

blocks|key|1309160|text|有一个KVC对象操作符，它提供了一个更优雅的解决方案，这是一个NSArray+category。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1309161|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/pm-dev/PMUtils/blob/master/Pod/Classes/Foundation%252BPMUtils/NSArray%252BPMUtils.m#L65-70^0|V|G|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

There's a KVC Object Operator that offers a more elegant solution <code>uniquearray = [yourarray valueForKeyPath:@"@distinctUnionOfObjects.self"];</code> Here's an <a href="https://github.com/pm-dev/PMUtils/blob/master/Pod/Classes/Foundation%2BPMUtils/NSArray%2BPMUtils.m#L65-70" rel="nofollow">NSArray category</a>.

blocks|key|1309211|text|在数组中添加对象之前，您可以尝试一种更简单的方法，它不会添加重复的值：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1309212|//假设mutableArray已分配并初始化，且包含某个值|1309213|if+(![yourMutableArray+containsObject:someValue])
{
+++[yourMutableArray+addObject:someValue];
}|code-block|syntax|javascript|1309214|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

One more simple way you can try out which will not add duplicate Value before adding object in array:-

//Assume mutableArray is allocated and initialize and contains some value

<pre><code>if (![yourMutableArray containsObject:someValue])
{
 [yourMutableArray addObject:someValue];
}
</code></pre>

blocks|key|1309388|text|从Objective-C中的NSMutableArray中删除重复的值|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1309389|NSMutableArray+*datelistArray+=+[[NSMutableArray+alloc]init];
for+(Student+*+data+in+fetchStudentDateArray)
{
++++if([datelistArray+indexOfObject:data.date]+==+NSNotFound)
++++[datelistArray+addObject:data.date];
}|code-block|syntax|javascript|1309390|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|$]]

Remove duplicate values from NSMutableArray in Objective-C

<pre><code>NSMutableArray *datelistArray = [[NSMutableArray alloc]init];
for (Student * data in fetchStudentDateArray)
{
 if([datelistArray indexOfObject:data.date] == NSNotFound)
 [datelistArray addObject:data.date];
}
</code></pre>

blocks|key|1524409|text|使用Orderedset可以做到这一点。这将保留从数组中删除重复项，并维护通常不能执行的集合的顺序|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1524410|entityMap^0|2|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Using <code>Orderedset</code> will do the trick. This will keep the remove duplicates from the array and maintain order which sets normally doesn't do

blocks|key|1308944|text|只需使用以下简单代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1308945|NSArray+*hasDuplicates+=+/*+(...)+*/;
NSArray+*noDuplicates+=+[[NSSet+setWithArray:+hasDuplicates]+allObjects];|code-block|syntax|javascript|1308946|因为nsset不允许重复值，并且所有对象都返回一个数组|1308947|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|$]]

just use this simple code :

<pre><code>NSArray *hasDuplicates = /* (...) */;
NSArray *noDuplicates = [[NSSet setWithArray: hasDuplicates] allObjects];
</code></pre>

since nsset doesn't allow duplicate values and all objects returns an array

The best way to remove duplicate values (<code>NSString</code>) from <code>NSMutableArray</code> in Objective-C?

Is this the easiest and right way to do it?

<pre><code>uniquearray = [[NSSet setWithArray:yourarray] allObjects];
</code></pre>

The best way to remove duplicate values from NSMutableArray in Objective-C?

在Objective-C中从NSMutableArray中删除重复值(NSString)的最佳方法是什么？这是最简单、最正确的方法吗？uniquearray = [[NSSet setWithArray:yourarray] allObjects];

问在Objective-C中从NSMutableArray中删除重复值的最好方法是什么？
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问在Objective-C中从NSMutableArray中删除重复值的最好方法是什么？
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