blocks|key|1398730|text|我会做以下事情-|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1398731|if([unkownArray+isKindOfClass:[NSMutableArray+class]]){
++//+This+is+a+nsmutable+array
}
else+if+([unkownArray+isKindOfClass:[NSArray+class]]){
+//+This+is+a+nsarray
}|code-block|syntax|javascript|1398732|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|$]]

I would do the following- 

<pre><code>if([unkownArray isKindOfClass:[NSMutableArray class]]){
 // This is a nsmutable array
}
else if ([unkownArray isKindOfClass:[NSArray class]]){
 // This is a nsarray
}
</code></pre>

blocks|key|1183239|text|请参阅NSObject's+-class方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1183240|NSLog(@"myUnknownArray+is+of+type:+%25@",+[myUnknownArray+class]);|code-block|syntax|javascript|1183241|您还可以使用%2Bclass方法进行更直接的检查：|1183242|BOOL+isMutableArray+=+[myUnknownArray+isKindOfClass:[NSMutableArray+class]];|1183243|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.apple.com/mac/library/documentation/cocoa/reference/Foundation/Protocols/NSObject_Protocol/Reference/NSObject.html#//apple_ref/occ/intfm/NSObject/class|1|http://developer.apple.com/mac/library/documentation/cocoa/reference/Foundation/Classes/NSObject_Class/Reference/Reference.html#//apple_ref/doc/uid/20000050-class^0|E|6|3|H|0|0|0|6|6|6|6|1|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@$9|11|A|12|1|13]]|E|$]]|$1|F|3|G|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|M|3|N|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]]]

See <a href="http://developer.apple.com/mac/library/documentation/cocoa/reference/Foundation/Protocols/NSObject_Protocol/Reference/NSObject.html#//apple_ref/occ/intfm/NSObject/class" rel="nofollow noreferrer">NSObject's <code>-class</code></a> method:

<pre><code>NSLog(@"myUnknownArray is of type: %@", [myUnknownArray class]);
</code></pre>

You can also check more directly with the <a href="http://developer.apple.com/mac/library/documentation/cocoa/reference/Foundation/Classes/NSObject_Class/Reference/Reference.html#//apple_ref/doc/uid/20000050-class" rel="nofollow noreferrer"><code>+class</code></a> method:

<pre><code>BOOL isMutableArray = [myUnknownArray isKindOfClass:[NSMutableArray class]];
</code></pre>

blocks|key|1398783|text|使用...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1398784|[数组isKindOfClass:NSMutableArray类]|1398785|[Array+isKindOfClass:NSArray类]|1398786|这将工作得很好。|1398787|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Use ...

[Array isKindOfClass:[NSMutableArray class]]

[Array isKindOfClass:[NSArray class]]

This will work fine.

blocks|key|1398856|text|下面是我的小测试代码，其结果如下。它演示了验证Foundation集合对象的可变性的技术。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1398857|请注意，可变版本(例如NSMutableArray)继承自不可变版本(NSArray)，因此需要注意类的测试。|offset|length|style|CODE|1398858|此外，对仅可变方法的实现的测试似乎可以找到工作，但可能比测试类慢一点。|1398859|无论如何-避免使用@try和@catch来尝试改变不可变对象，根据苹果文档，这些不应该在部署代码中使用-因为异常会导致堆栈展开，这是特别昂贵的，也会阻止和无效许多优化。|1398860|id+arr1+=+[NSArray+arrayWithObjects:@"Motti",@"name",@55,+@"age",+nil];
id+arr2+=+[NSMutableArray+arrayWithObjects:@"Motti",@"name",@55,+@"age",+nil];

NSLog+(@"arr1+isKindOfClass+NSArray:%25@,+NSMutableArray:%25@",+[arr1+isKindOfClass:[NSArray+class]]+?+@"YES"+:+@"NO",+[arr1+isKindOfClass:[NSMutableArray+class]]+?+@"YES"+:+@"NO");
NSLog+(@"arr2+isKindOfClass+NSArray:%25@,+NSMutableArray:%25@",+[arr2+isKindOfClass:[NSArray+class]]+?+@"YES"+:+@"NO",+[arr2+isKindOfClass:[NSMutableArray+class]]+?+@"YES"+:+@"NO");

NSLog+(@"arr1+implements+insertObject:atIndex:%25@",+[arr1+respondsToSelector:+@selector(insertObject:atIndex:)]+?+@"YES"+:+@"NO");
NSLog+(@"arr2+implements+insertObject:atIndex:%25@",+[arr2+respondsToSelector:+@selector(insertObject:atIndex:)]+?+@"YES"+:+@"NO");

id+dict1+=+[NSDictionary+dictionaryWithObjectsAndKeys:@"Motti",@"name",@55,+@"age",+nil];
id+dict2+=+[NSMutableDictionary+dictionaryWithObjectsAndKeys:@"Motti",@"name",@55,+@"age",+nil];

NSLog+(@"dict1+isKindOfClass+NSDictoinary:%25@,+NSMutableDictionary:%25@",+[dict1+isKindOfClass:[NSDictionary+class]]+?+@"YES"+:+@"NO",+[dict1+isKindOfClass:[NSMutableDictionary+class]]+?+@"YES"+:+@"NO");
NSLog+(@"dict2+isKindOfClass+NSDictoinary:%25@,+NSMutableDictionary:%25@",+[dict2+isKindOfClass:[NSDictionary+class]]+?+@"YES"+:+@"NO",+[dict2+isKindOfClass:[NSMutableDictionary+class]]+?+@"YES"+:+@"NO");

NSLog+(@"dict1+implements+setObject:forKey:%25@",+[dict1+respondsToSelector:+@selector(setObject:forKey:)]+?+@"YES"+:+@"NO");
NSLog+(@"dict2+implements+setObject:forKey:%25@",+[dict2+respondsToSelector:+@selector(setObject:forKey:)]+?+@"YES"+:+@"NO");|code-block|syntax|javascript|1398861|和结果打印输出：|1398862|14:30:42.2683+Test[381:286]+arr1+isKindOfClass+NSArray:YES,+NSMutableArray:NO
14:30:42.2683+Test[381:286]+arr2+isKindOfClass+NSArray:YES,+NSMutableArray:YES
14:30:42.2684+Test[381:286]+arr1+implements+insertObject:atIndex:NO
14:30:42.2684+Test[381:286]+arr2+implements+insertObject:atIndex:YES
14:30:42.2684+Test[381:286]+dict1+isKindOfClass+NSDictoinary:YES,+NSMutableDictionary:NO
14:30:42.2685+Test[381:286]+dict2+isKindOfClass+NSDictoinary:YES,+NSMutableDictionary:YES
14:30:42.2686+Test[381:286]+dict1+implements+setObject:forKey:NO
14:30:42.2687+Test[381:286]+dict2+implements+setObject:forKey:YES|1398863|entityMap^0|0|B|E|Z|7|0|0|9|4|E|6|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@$D|Y|E|Z|F|G]|$D|10|E|11|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|12|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|13|8|@$D|14|E|15|F|G]|$D|16|E|17|F|G]]|9|@]|A|$]]|$1|L|3|M|5|N|7|18|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|19|8|@]|9|@]|A|$]]|$1|S|3|T|5|N|7|1A|8|@]|9|@]|A|$O|P]]|$1|U|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|V|$]]

Here's my little test code, with its results below. It demonstrates the technique of verifying mutability of Foundation collection objects.
Take note that the mutable versions (e.g. <code>NSMutableArray</code>) inherit from the immutable ones (<code>NSArray</code>) and so testing for the class needs attention.
Also the test for implementation of mutable-only methods seems to work find, but may be a little slower than the test of class.
In any way - AVOID using <code>@try</code> and <code>@catch</code> to attempt mutating immutable objects, according to Apple docs these should not be used in deployment code- since exceptions cause stack unrolling which is specifically costly and also prevents and voids lots of optimizations.
<pre><code>id arr1 = [NSArray arrayWithObjects:@&quot;Motti&quot;,@&quot;name&quot;,@55, @&quot;age&quot;, nil];
id arr2 = [NSMutableArray arrayWithObjects:@&quot;Motti&quot;,@&quot;name&quot;,@55, @&quot;age&quot;, nil];

NSLog (@&quot;arr1 isKindOfClass NSArray:%@, NSMutableArray:%@&quot;, [arr1 isKindOfClass:[NSArray class]] ? @&quot;YES&quot; : @&quot;NO&quot;, [arr1 isKindOfClass:[NSMutableArray class]] ? @&quot;YES&quot; : @&quot;NO&quot;);
NSLog (@&quot;arr2 isKindOfClass NSArray:%@, NSMutableArray:%@&quot;, [arr2 isKindOfClass:[NSArray class]] ? @&quot;YES&quot; : @&quot;NO&quot;, [arr2 isKindOfClass:[NSMutableArray class]] ? @&quot;YES&quot; : @&quot;NO&quot;);

NSLog (@&quot;arr1 implements insertObject:atIndex:%@&quot;, [arr1 respondsToSelector: @selector(insertObject:atIndex:)] ? @&quot;YES&quot; : @&quot;NO&quot;);
NSLog (@&quot;arr2 implements insertObject:atIndex:%@&quot;, [arr2 respondsToSelector: @selector(insertObject:atIndex:)] ? @&quot;YES&quot; : @&quot;NO&quot;);

id dict1 = [NSDictionary dictionaryWithObjectsAndKeys:@&quot;Motti&quot;,@&quot;name&quot;,@55, @&quot;age&quot;, nil];
id dict2 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@&quot;Motti&quot;,@&quot;name&quot;,@55, @&quot;age&quot;, nil];

NSLog (@&quot;dict1 isKindOfClass NSDictoinary:%@, NSMutableDictionary:%@&quot;, [dict1 isKindOfClass:[NSDictionary class]] ? @&quot;YES&quot; : @&quot;NO&quot;, [dict1 isKindOfClass:[NSMutableDictionary class]] ? @&quot;YES&quot; : @&quot;NO&quot;);
NSLog (@&quot;dict2 isKindOfClass NSDictoinary:%@, NSMutableDictionary:%@&quot;, [dict2 isKindOfClass:[NSDictionary class]] ? @&quot;YES&quot; : @&quot;NO&quot;, [dict2 isKindOfClass:[NSMutableDictionary class]] ? @&quot;YES&quot; : @&quot;NO&quot;);

NSLog (@&quot;dict1 implements setObject:forKey:%@&quot;, [dict1 respondsToSelector: @selector(setObject:forKey:)] ? @&quot;YES&quot; : @&quot;NO&quot;);
NSLog (@&quot;dict2 implements setObject:forKey:%@&quot;, [dict2 respondsToSelector: @selector(setObject:forKey:)] ? @&quot;YES&quot; : @&quot;NO&quot;);
</code></pre>
and the results printout:
<pre><code>14:30:42.2683 Test[381:286] arr1 isKindOfClass NSArray:YES, NSMutableArray:NO
14:30:42.2683 Test[381:286] arr2 isKindOfClass NSArray:YES, NSMutableArray:YES
14:30:42.2684 Test[381:286] arr1 implements insertObject:atIndex:NO
14:30:42.2684 Test[381:286] arr2 implements insertObject:atIndex:YES
14:30:42.2684 Test[381:286] dict1 isKindOfClass NSDictoinary:YES, NSMutableDictionary:NO
14:30:42.2685 Test[381:286] dict2 isKindOfClass NSDictoinary:YES, NSMutableDictionary:YES
14:30:42.2686 Test[381:286] dict1 implements setObject:forKey:NO
14:30:42.2687 Test[381:286] dict2 implements setObject:forKey:YES
</code></pre>

blocks|key|1398689|text|你必须使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1398690|[yourArray+isKindOf:+[NSArray+class]]|code-block|syntax|javascript|1398691|因为类的简单比较可能会失败，因为您的数组可能不是NSArray，而是其他一些低级类型。您还可以检查您的数组是否响应所需的方法。|1398692|[yourArray+respondsToSelector:+@selector(addObject:)]|1398693|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|$]]

You have to use:

<pre><code>[yourArray isKindOf: [NSArray class]]
</code></pre>

since a simple comparization of the classes may fail because your array is probably not a NSArray but of some other low level type. You may also check if your array responds to the methods you need.

<pre><code>[yourArray respondsToSelector: @selector(addObject:)]
</code></pre>

How can i check if a variable is an NSArray or an NSMutableArray?

Objective C: how to check if variable is NSArray or NSMutableArray

如何检查变量是NSArray还是NSMutableArray？

问目标C:如何检查变量是NSArray还是NSMutableArray
EN

回答 5

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问目标C:如何检查变量是NSArray还是NSMutableArray
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