Objective-c----nsdictionary, nsmutabledictionary

Knowledge Points:

Definition: A dictionary (dictionary) is a collection of keywords and their definitions.

On the code:

/ * * nsdictionary Immutable Dictionary * */        ///1, common methods for creating dictionary objects        you need to assign key-value pairs when you have a Dictionary object in the bedstead, but in order: value, key (value in front, key in back form).         nsdictionary*dic1 = [[nsdictionaryAlloc] initwithobjectsandkeys:@"Wang", @"Name", @ -, @"Age", @"Man", @"Gender",Nil] ;NSLog( @"%@", Dic1);nsdictionary*dic2 = [nsdictionarydictionarywithobjectsandkeys:@"Zhen", @"Name", @ A, @"Age", @"NV", @"Gender",Nil] ;NSLog( @"%@", Dic2);Nsarray*keys = @[@"Name", @"Age", @"Gender"] ;Nsarray*values = @[@"Wang", @ -, @"Male"] ;//Create a Dictionary object when the number of two array elements must be the same        nsdictionary*DIC3 = [[nsdictionaryAlloc] Initwithobjects:values Forkeys:keys];NSLog( @"%@", DIC3);nsdictionary*DIC4 = [nsdictionaryDictionarywithobjects:values Forkeys:keys];NSLog( @"%@", DIC4);//Gets the number of key-value pairs in the dictionary by the Count method        NSLog( @"%ld", [Dic4 Count]);//Get all the keys in the dictionary        Nsarray*allkeys = [Dic4 AllKeys];NSLog( @"%@", AllKeys);//Get all the values in the dictionary        Nsarray*allvalues = [Dic4 allvalues];NSLog( @"%@", allvalues);//get its corresponding value in the dictionary by the specified key        IDObject = [Dic4 objectforkey:@"Age"] ;NSLog( @"%@", object); for(inti =0; i < [dic4 count]; i++) {IDkey = [AllKeys objectatindex:i];IDValue = [Dic4 Objectforkey:key];NSLog( @"%@", value);//[nsstring class] Returns an object of type NSString            //iskindofclass Determines whether value is an object of type NSString            NSString*result = [Value iskindofclass:[NSStringClass]]? @"YES": @"NO";NSLog( @"%@:%@-->%@", key, value, result); }//Dictionary of Syntactic sugar forms (note ': ' and ', ' are paired up)        nsdictionary*DIC5 = @{@"Name": @"Wang", @"Age": @ -, @"Gender": @"Man"} ;NSLog( @"%@", DIC5);/ * * nsmutabledictionary Variable dictionary * */        //initwithdictionary and Dictionarywithdictionary can change immutable dictionaries into mutable dictionaries        nsmutabledictionary*DIC6 = [[nsmutabledictionaryAlloc] INITWITHDICTIONARY:DIC5];NSLog( @"%@", DIC6);nsmutabledictionary*dic7 = [nsmutabledictionaryDICTIONARYWITHDICTIONARY:DIC5];NSLog( @"%@", DIC7);//Two types of initialization methods        nsmutabledictionary*dic8 = [[nsmutabledictionaryALLOC] init];NSLog( @"%@", DIC8);nsmutabledictionary*DIC9 = [nsmutabledictionaryDictionary];NSLog( @"%@", DIC9);//Increase key-value pairs[Dic9 setobject:@"Wang"forkey:@"Name"] ; [Dic9 setobject:@331forkey:@"Age"] ; [Dic9 setobject:@"Mam"forkey:@"Gender"] ;NSLog( @"%@", DIC9);//Modify the value of the existing key (note: If the key is already present, modify the corresponding value, add this key value pair if it does not exist)[Dic9 setobject:@ theforkey:@"Age"] ;NSLog( @"%@", DIC9);//To delete the corresponding key-value pair according to the specified key[Dic9 removeobjectforkey:@"Age"] ;NSLog( @"%@", DIC9);//Delete all key-value pairs[Dic9 removeallobjects];NSLog( @"%@", DIC9);

Objective-c----nsdictionary, nsmutabledictionary