如何从NSDictionary获取键/值对？

Question

我对NSDictionary的帮助不大。我如何得到1对，如果我有字典，就说“id”的值

NSDictionary *allCourses = [NSJSONSerialization JSONObjectWithData:allCoursesData options:NSJSONReadingMutableContainers error:&error];

它看起来像这样：

感谢您的帮助。

Answer 1

最短路：

NSNumber *number = allCourses[@"semacko"][@"id"];

Answer 2

试试这个：

NSDictionary *allCourses = [NSJSONSerialization JSONObjectWithData:allCoursesData options:NSJSONReadingMutableContainers error:&error];
        [allCourses enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop) {
    // do something with key and obj
}];

Answer 3

NSDictionary *semacko = [allCourses objectForKey:@"semacko"];
NSNumber *number = [semacko objectForKey:@"id"];

Answer 4

NSNumber *number = allCourses[@"semacko"][@"id"];

或者如果你想迭代所有对象：

for(NSDictionary* course in allCourses) {
    NSNumber *number = course[@"id"];
}

Answer 5

NSString *name =[[NSString alloc]initWithFormat:@"%@",[Dictionaryname objectForKey:@"key"]];

通过此代码，您可以访问与objectforkey关键字

中指定的键对应的值

Answer 6

您可以尝试：

NSNumber *courseID = [allCourses valueForKeyPath:@"semacko.id"];

设置值：

- setValue:forKeyPath: