if (dict != nil && dict.containsObjectForKey[@"a"]) { ... } Can become this: if (dict.containsObjectForKey[@"a"]) { ... } This is probably the lea

if (dict != nil && dict.containsObjectForKey[@"a"]) { ... } Can become this: if (dict.containsObjectForKey[@"a"]) { ... } This is probably the least-Swift thing ever, but, if you're used to coding in this style, it's fantastic Why is this better than a language that can guarantee that dict is not null?