Objective-C的：数出数组中出现的对象的次数？ [英] Objective-C: Count the number of times an object occurs in an array?

问题描述

我需要执行什么，我觉得是一个基本的功能，但我无法找到如何做的文档。请帮助！

I need to perform what I feel is a basic function but I can't find any documentation on how to do it. Please help!

我需要计数某个对象以阵列多少次发生。见例如：

I need to count how many times a certain object occurs in an array. See example:

array = NSArray arrayWithObjects:@"Apple", @"Banana", @"Cantaloupe", @"Apple", @"DragonFruit", @"Eggplant", @"Apple", @"Apple", @"Guava",nil]retain];

我

如何通过遍历数组和计数的次数就找到字符串@苹果？

How can I iterate through the array and count the number of times it finds the string @"Apple"?

任何帮助AP preciated！

Any help is appreciated!

推荐答案

一个简单而明确的答案：

A Simple and specific answer:

int occurrences = 0;
for(NSString *string in array){
    occurrences += ([string isEqualToString:@"Apple"]?1:0); //certain object is @"Apple"
}
NSLog(@"number of occurences %d", occurrences);

PS：马丁Babacaev的答案是相当不错了。迭代更快地块，但与我猜没有明显的增益，使几个要素这种特殊情况下。我会用，虽然：）

PS: Martin Babacaev's answer is quite good too. Iteration is faster with blocks but in this specific case with so few elements I guess there is no apparent gain. I would use that though :)

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