ios - Objective-C解析Json并检查响应是否是对象数组中的单个对象

Question

我从互联网上读取了一个json文件。它包含一个或多个源。使用我的代码，如果用户只有一个来源，则应用程序崩溃

NSDictionary *results = [stringSubscriptions JSONValue];

for (NSDictionary *element in results){
    SubscriptionArray *add = [[SubscriptionArray alloc] init];
    add.title=[element objectForKey:@"title"];
    add.source=[element objectForKey:@"website"];
    add.htmlUrl=[element objectForKey:@"id"];
    add.count=0;
    [onlySubsriptions addObject:add];
    [add release];

}

我怎么解决这个问题？
谢谢

两个或多个对象

[
    {
        "website": "http://www.ispazio.net", 
        "updated": 1392645040345, 
        "title": "iSpazio - IL Blog Italiano per le Notizie sull'iPhone 5S, iPhone 5C, 5 e 4S con recensioni App Store e Guide al Jailbreak", 
        "topics": [
            "Apple", 
            "iphone", 
            "Tecnologia", 
            "Tech", 
            "Mac"
        ], 
        "sortid": "26152F8F", 
        "velocity": 196.0, 
        "id": "feed/http://feeds.feedburner.com/Ispazio", 
        "categories": []
    }, 
    {
        "website": "http://www.xataka.com", 
        "updated": 1392640863251, 
        "title": "Xataka", 
        "topics": [
            "Tecnología", 
            "Tecnologia", 
            "Gadgets", 
            "Tech"
        ], 
        "velocity": 92.200000000000003, 
        "id": "feed/http://feeds.weblogssl.com/xataka2", 
        "categories": []
    }
]

一个对象

{
    "website": "http://www.ispazio.net", 
    "updated": 1392645040345, 
    "title": "iSpazio - IL Blog Italiano per le Notizie sull'iPhone 5S, iPhone 5C, 5 e 4S con recensioni App Store e Guide al Jailbreak", 
    "topics": [
        "Apple", 
        "iphone", 
        "Tecnologia", 
        "Tech", 
        "Mac"
    ], 
    "sortid": "26152F8F", 
    "velocity": 196.0, 
    "id": "feed/http://feeds.feedburner.com/Ispazio", 
    "categories": []
}

Answer 1

您可以检查结果对象是哪种类，请尝试如下操作:

id result = [stringSubscriptions JSONValue];
if ([result isKindOfClass:[NSArray class])
    NSLog(@"NSArray");
else if ([result isKindOfClass:[NSDictionary class])
    NSLog(@"NSDictionary");