From CocoaHeads:

To sum it up, you can create an NSDictionary through the following:

`dict = @{ k1 : o1, k2 : o2, k3 : o3 };`

Similarly for an NSArray:

`array = @[ a, b, c ];`

and for NSNumber:

`NSNumber *number;`

number = @'X';

number = @12345;

number = @12345ul;

number = @12345ll;

number = @123.45f;

number = @123.45;

number = @YES;

Find the entire article at CocoaHeads • Objective-C literals for NSDictionary, NSArray, and NSNumber.