Question

我有一个带有url字符串属性和标题的历史对象。我想使用包含搜索字符串的url搜索所有对象的历史记录，然后删除所有重复项。

实施例：我有一个历史对象数组，其中20个都是“https://www.google.com”，4个是“https://www.google.com/#q=search”，我想得到一个只有一个对象的数组，其url值为“{{ 3}}“和一个网址值”https://www.google.com“

这是我当前的代码，它搜索历史记录并返回与字符串匹配的所有对象：

    - (NSArray *)historyObjectsContainingQuery:(NSString *)query {
    NSMutableArray *matchingObjects = [[NSMutableArray alloc] init];
    HistoryManager *HM = [HistoryManager sharedInstance];
    for (int i=0; i<[[HM history] count]; i++) {
        //History "days"
        HistoryObject *historyItem = HistoryObject([[HistoryManager sharedInstance] history][i]);

        for (int o=0; o<[historyItem.objects count]; o++) {
            //Each object inn each history day
            HistoryObject *HO = HistoryObject(historyItem.objects[o]);
            if ([HO.title rangeOfString:query options:NSCaseInsensitiveSearch].location != NSNotFound) {
                //history objects with their title containing the query string
                [matchingObjects addObject:HO];
            }
        }
    }
    return matchingObjects;
}

然后我记录每个网址值：

self.foundInBookmarksAndHistory = [self historyObjectsContainingQuery：textField.text]; for（HistoryObject * HO in self.foundInBookmarksAndHistory）{ 的NSLog（@ “％@”，HO.url）; }

以下是结果：

https://www.google.com/
2013-09-15 13:48:49.382 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.384 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.385 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.387 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.388 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.390 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.391 Flow HD[3599:60b] https://www.google.com/search?q=yahoo
2013-09-15 13:48:49.392 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.394 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.395 Flow HD[3599:60b] https://www.google.com/search?q=Sup
2013-09-15 13:48:49.397 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.398 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.400 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.402 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.404 Flow HD[3599:60b] https://www.google.com/
2013-09-15 13:48:49.405 Flow HD[3599:60b] https://www.google.com/

还有很多，我如何删除具有相同值的每个对象？对象不相等，但确实有相同的URL。

我已经尝试过NSPredicate并使用更多for循环来查找匹配的对象，但我总是留下2个或更多具有相同属性的相同对象。

Answer 1

你可以这样做：

NSMutableSet *seenObjects = [NSMutableSet set];
NSPredicate *dupPred = [NSPredicate predicateWithBlock: ^BOOL(id obj, NSDictionary *bind) {
    HistoryObject *hObj = (HistoryObject*)obj;
    BOOL seen = [seenObjects containsObject:hObj.title];
    if (!seen) {
        [seenObjects addObject:hObj.title];
    }
    return !seen;
}];
NSArray *yourHistoryArray = ... // This is your array which needs to be filtered
NSArray *yourHistoryArray = [yourHistoryArray filteredArrayUsingPredicate:dupObjectsPred];

Answer 2

我不确定这是搜索所有对象的最佳方式，但除了我能想到的最简单的修补程序，您的代码就是替换

if ([HO.title rangeOfString:query options:NSCaseInsensitiveSearch].location != NSNotFound) {
                [matchingObjects addObject:HO];
            }

用这个：

if ([HO.title rangeOfString:query options:NSCaseInsensitiveSearch].location != NSNotFound) {
                HistoryObject *temp = HistoryObject(historyItem.objects[o]);
                [historyItem.objects removeObjectAtIndex:o];
            }

//And after all the `for` loops 

[historyItem.objects addObject:temp];

您删除了所有匹配的对象，并将其添加到阵列一次。

修改阅读完修改后，请使用isEqualToString代替rangeOfString。 rangeOfString会在abcd，abce和abcf中找到abc这个词，这不是你想要的。对于abc，isEqualToString仅对abc有效，没有别的。

Answer 3

循环可变数组（如果对象仍然存在，则将数组更改为可变）

while ([farray containsObject:_data]){
       [farray removeObject:_data];
}

如何删除具有相同属性值但在NSMutableArray中具有相同属性值的所有对象

3 个答案: