iOS Components and Frameworks: Understanding the Advanced Features of the iOS SDK

NSDictionary

To declare and instantiate an NSDictionary with a known set of keys and values previously, a class method or equivalent alloc/init needed to be used:

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NSDictionary *workDict =[NSDictionarydictionaryWithObjectsAndKeys:@"float",floatNumber, @"integer", integerNumber, @"array",workArray, nil];

With the new syntax, declaring and instantiating an NSDictionary is much simpler, much less verbose, and easier to read:

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NSDictionary *workDict = @{ @"float": floatNumber,                         @"integer" : integerNumber,                         @"array" : workArray };

Be sure to note, however, that putting a nil object as either a key or a value either will cause a warning if the compiler ...