NSArray *arrayOfAnthonysChildren = [[NSArray alloc]initWithObjects:@"Anthony's Son 1",@"Anthony's Danghter 1",@"Anthony's Son 2",@"Anthony's Son 3",@"Anthony's Daughter 2",nil];

[dictionary setValue: arrayOfAnthonysChildren forKey:@"children"];

NSError *error = nil;

NSData *jsonData = [NSJSONSerialization dataWithISONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error];

if([jsonData length]>0 && error == nil){

    NSLog(@"Successfully serializes the dictionary into data = %@,jsonData");

}else if([jsonData length] == 0 && error == nil){

    NSLog(@"No data returned after serialization.");

}else if(error != nil){

    NSLog(@"An error happened = %@",error);

}

运行结果：

successfully serialized the dictionary into data.

JSON String = {

"Last Name" : "Robbins", "First Name" : "Anthony", "children" : [

"Anthony's Son 1", "Anthony's Daughter 1", "Anthony's Son 2", "Anthony's Son 3", "Anthony's Daughter 2"

],

"Age" : 51 }

把json数据转化成Arrays 或者Dictionaries 

希望把一个json数据解析出来放在数据或者字典里保存，通过NSJSONSerialization 这个类的 JSONObjectWithData：options：error：方法来实现

error = nil;

id jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments error:&error];

if(jsonObject != nil && error == nil){

    NSLog(@"Successfully deserialized … ");

    if([jsonObject isKindOfClass:[NSDictionary class]]){

        NSDictionary *deserializedDictionary = (NSDictionary *)jsonObject;

        NSLog(@"Dersialized JSON Dictionary = %@",deserializedDictionary);

    }else if([jsonObject isKindOfClass:[NSArray class]]){

        NSArray *deserializedArray = (NSArray *)jsonObject;

        NSLog(@"Dersialized JSON Array =%@",deserializedArray);

    }

}

else if(error != nil){

   NSLog(@"An error happened while deserializing the JSON data.");

}