Question

I recently came across some symbols in an Xcode project that I haven’t noticed before.

What is

@{some_value} and

@[some_value]

Thank you

Answer 1

It should be @{key:value} which represents a dictionary with key and value. @[some_value] should be an array. As mentioned in the other answer, check Objective C Literals for more details.

From that link an example is,

NSDictionary *dictionary = @{
    @"name" : @"some name",
    @"date" : [NSDate date],
    @"processInfo" : [NSProcessInfo processInfo]
};

NSArray *array = @[ @"Hello", NSApp, @42]];