The differences between dictionaries SetValue and SetObject

Note: Setobject:forkey: The object in key is an ID type, not a nsstring, but we often use nsstring.

1, Setobject:forkey: In value is not able to nil, or will error.

Setvalue:forkey: Value can be nil, but when value is nil, the Removeobject:forkey method is called automatically

2, Setvalue:forkey: The parameter in key can only be nsstring type, and Setobject:forkey: can be any type

Note: Setobject:forkey: objects cannot hold nil to differentiate from this situation:

nsmutabledictionary* dic [email protected] {@ "K1": @ " good person", @ "K2": @ " bad guy" @ "K3": @ " man" @ "K4": @ " woman"};

1, [dic setobject:[nsnullnull] forkey:@ "K5"];

[NSNull null] represents an empty object, not nil, note this

The differences between dictionaries SetValue and SetObject