使用JSONKit将字符串，字典，数组转换成json格式

NSString *str = nil;

//字符串
   
NSMutableString *string = [[NSMutableString alloc] init];
    [string
appendString:@"xxxx"];
    str =
[string JSONString];
   
NSLog(@"str1:%@",[NSString stringWithString:str]);
    
    
    //数组
    NSArray
*array = [[NSArray alloc] initWithObjects:@"111",@"333",@"222",
nil];
   // NSMutableArray *array =
[NSMutableArray array];
    str = [array
JSONString];
   
NSLog(@"str2:%@",[NSString stringWithString:str]);
    [array
release ];
    
    //字典
    NSArray
*firstArr = [NSArray arrayWithObjects:@"first",@"second",
nil];
   
//基本数据类型转换成NSNumber类型
    NSArray
*secondArr = [NSArray arrayWithObjects:[NSNumber
numberWithDouble:2.1],[NSNumber numberWithBool:NO], nil];
   
//加到字典中
    NSDictionary
*dic = [NSDictionary
dictionaryWithObjectsAndKeys:firstArr,@"first",secondArr,@"second",
nil];
   
//转化成json格式
    str = [dic
JSONString];
    NSString
*str2 = [NSString stringWithString:str];
   
NSLog(@"str3:%@",str2);
    
    //编码
    NSData
*archive = [NSKeyedArchiver
archivedDataWithRootObject:array];
//   
NSLog(@"archive:%@",archive);
    NSArray
*arr2 = [NSKeyedUnarchiver unarchiveObjectWithData:archive];
   
NSLog(@"arr2:%@",arr2);