比較NSMutableArray元素的值

Question

我正在尋找一種方法來比較兩個NSMutableArray對象的內容。這兩個數組都填充了NSMutableDictionaries，它們分開分配，但偶爾包含相同的數據。

簡化的例子：

NSMutableArray *firstArray = [[NSMutableArray alloc] init]; 
NSMutableArray *secondArray = [[NSMutableArray alloc] init]; 

NSMutableDictionary *a = [[NSDictionary alloc] init]; 
[a setObject:@"foo" forKey:"name"]; 
[a setObject:[NSNumber numberWithInt:1] forKey:"number"]; 

NSMutableDictionary *b = [[NSDictionary alloc] init]; 
[b setObject:@"bar" forKey:"name"]; 
[b setObject:[NSNumber numberWithInt:2] forKey:"number"]; 

NSMutableDictionary *c = [[NSDictionary alloc] init]; 
[c setObject:@"foo" forKey:"name"]; 
[c setObject:[NSNumber numberWithInt:1] forKey:"number"]; 

[firstArray addObject:a]; 
[firstArray addObject:b]; 
[secondArray addObject:c]; 

a，b和c是不同的對象，但a和c匹配的內容。

我在找什麼是比較firstArray和secondArray並僅返回b的函數/方法。

僞代碼：

NSArray *difference = [self magicFunctionWithArray:firstArray andArray:secondArray]; 
NSLog(@"%@",difference) 

=> ({name="bar"; number=2}) 

預先感謝您。

Answer 1

這可以使用NSMutableSet實例來實現。

NSMutableSet * firstSet = [NSMutableSet setWithArray:firstArray]; 
NSMutableSet * secondSet = [NSMutableSet setWithArray:firstArray]; 

[firstSet unionSet:[NSSet setWithArray:secondArray]]; 
[secondSet intersectSet:[NSSet setWithArray:secondArray]]; 

[firstSet minusSet:secondSet]; 

NSLog(@"%@", firstSet);