如何知道NSArray中是否添加了新元素

Question

随着时间的推移，我有一个巨大的array=["1","2","3","4","5","6"]。

例如：它将是array=["1","2","3","4","5","6","10","11"]。

如何知道两个元素增加了大量？在示例中，添加的新元素是10和11。

Answer 1

所以基本上你只需要删除旧元素并显示新元素。

您可以尝试使用removeOjbectsInArray

的NSMutableArray方法

i.e.
NSArray *oldArray = @[@"1",@"2",@"3",@"4",@"5",@"6"];
NSArray *newArray = @[@"1",@"2",@"3",@"4",@"5",@"6",@"10",@"11"];
NSMutableArray *result = [newArray mutableCopy]; // make sure you make it a mutable copy
// remove the existing elements
[result removeObjectsInArray:oldArray];
NSLog(@"remaining entry: %@",result);

输出

@[10,11];

Answer 2

试试这个，

<span class="js-display-url">product/poss/newslanges</span>

<强>输出：

NSArray *array1 = @[@"1",@"2",@"3",@"4",@"5",@"6"];
NSArray *array2 = @[@"1",@"2",@"3",@"4",@"5",@"6",@"10",@"11"];
NSMutableArray *addedArray = [NSMutableArray array];

for(int i = 0; i < [array2 count]; i++)
{
    if (![array1 containsObject:[array2 objectAtIndex:i]]) {
        [addedArray addObject:[array2 objectAtIndex:i]];
    }
}

NSLog(@"New elements is added: %@", addedArray);