{"firstName":"Brett","lastName":"McLaughlin","email":"aaaa"} 

{
  "programmers": [{
    "firstName": "Brett",
    "lastName": "McLaughlin",
    "email": "aaaa"
  }, {
    "firstName": "Elliotte",
    "lastName": "Harold",
    "email": "cccc"
  }],
  "authors": [{
    "firstName": "Isaac",
    "lastName": "Asimov",
    "genre": "sciencefiction"
  }, {
    "firstName": "Frank",
    "lastName": "Peretti",
    "genre": "christianfiction"
  }],
  "musicians": [{
    "firstName": "Eric",
    "lastName": "Clapton",
    "instrument": "guitar"
  }, {
    "firstName": "Sergei",
    "lastName": "Rachmaninoff",
    "instrument": "piano"
  }]
}

// 如果數(shù)組或者字典中存儲了 NSString, NSNumber, NSArray, NSDictionary, or NSNull 之外的其他對象,就不能直接保存成文件了.也不能序列化成 JSON 數(shù)據(jù).
  NSDictionary *dict = @{@"name" : @"me", @"do" : @"something", @"with" : @"her", @"address" : @"home"};
  
  // 1.判斷當前對象是否能夠轉(zhuǎn)換成JSON數(shù)據(jù).
  // YES if obj can be converted to JSON data, otherwise NO
  BOOL isYes = [NSJSONSerialization isValidJSONObject:dict];
  
  if (isYes) {
    NSLog(@"可以轉(zhuǎn)換");
    
    /* JSON data for obj, or nil if an internal error occurs. The resulting data is a encoded in UTF-8.
     */
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:0 error:NULL];
    
    /*
     Writes the bytes in the receiver to the file specified by a given path.
     YES if the operation succeeds, otherwise NO
     */
    // 將JSON數(shù)據(jù)寫成文件
    // 文件添加后綴名: 告訴別人當前文件的類型.
    // 注意: AFN是通過文件類型來確定數(shù)據(jù)類型的!如果不添加類型,有可能識別不了! 自己最好添加文件類型.
    [jsonData writeToFile:@"/Users/SunnyBoy/Sites/JSON_XML/dict.json" atomically:YES];
    
    NSLog(@"%@", [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]);
    
  } else {
    
    NSLog(@"JSON數(shù)據(jù)生成失敗，請檢查數(shù)據(jù)格式");
    
  }

　　 NSArray *array = @[@"qn", @18, @"ya", @"wj"];
  
  BOOL isYes = [NSJSONSerialization isValidJSONObject:array];
  
  if (isYes) {
    NSLog(@"可以轉(zhuǎn)換");
    
    NSData *data = [NSJSONSerialization dataWithJSONObject:array options:0 error:NULL];
    
    [data writeToFile:@"/Users/SunnyBoy/Sites/JSON_XML/base" atomically:YES];
  
  } else {
    
    NSLog(@"JSON數(shù)據(jù)生成失敗，請檢查數(shù)據(jù)格式");
    
  }

//使用TouchJson來解析北京的天氣
//獲取API接口
NSURL *url = [NSURL URLWithString:@"http://m.weather.com.cn/data/101010100.html"];

//定義一個NSError對象，用于捕獲錯誤信息
NSError *error;
NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];

NSLog(@"jsonString--->%@",jsonString);

//將解析得到的內(nèi)容存放字典中，編碼格式為UTF8，防止取值的時候發(fā)生亂碼
NSDictionary *rootDic = [[CJSONDeserializer deserializer] deserialize:[jsonString dataUsingEncoding:NSUTF8StringEncoding] error:&error];

//因為返回的Json文件有兩層，去第二層內(nèi)容放到字典中去
NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];
NSLog(@"weatherInfo--->%@",weatherInfo);

//取值打印
NSLog(@"%@",[NSString stringWithFormat:@"今天是 %@ %@ %@ 的天氣狀況是：%@ %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]]);

//使用SBJson解析北京的天氣
NSURL *url = [NSURL URLWithString:@"http://www.weather.com.cn/adat/sk/101010100.html"];

NSError *error = nil;

NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];

SBJsonParser *parser = [[SBJsonParser alloc] init];

NSDictionary *rootDic = [parser objectWithString:jsonString error:&error];

NSDictionary *weatherInfo = [rootDic objectForKey:@"weatherinfo"];

NSLog(@"%@", [NSString stringWithFormat:@"今天是 %@ %@ %@ 的天氣狀況是：%@ %@ ",[weatherInfo objectForKey:@"date_y"],[weatherInfo objectForKey:@"week"],[weatherInfo objectForKey:@"city"], [weatherInfo objectForKey:@"weather1"], [weatherInfo objectForKey:@"temp1"]]);

// 從中國天氣預報網(wǎng)請求數(shù)據(jù)
  NSURL *url = [ NSURL URLWithString:@"http://www.weather.com.cn/adat/sk/101010100.html"];
  
  // 創(chuàng)建請求
  NSURLRequest *request = [NSURLRequest requestWithURL:url];
  
  [[[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
    
    // 在網(wǎng)絡完成的 Block 回調(diào)中,要增加錯誤機制.
    // 失敗機制處理: 錯誤的狀態(tài)碼!
    
    // 最簡單的錯誤處理機制:
    if (data && !error) {
      
      // JSON格式轉(zhuǎn)換成字典，IOS5中自帶解析類NSJSONSerialization從response中解析出數(shù)據(jù)放到字典中
      id obj = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
      
      NSDictionary *dict = obj[@"weatherinfo"];
      
      NSLog(@"%@---%@", dict, dict[@"city"]);
    }
    
  }] resume];

//如果json是“單層”的，即value都是字符串、數(shù)字，可以使用objectFromJSONString
NSString *json1 = @"{\"a\":123, \"b\":\"abc\"}";
NSLog(@"json1:%@",json1);

NSDictionary *data1 = [json1 objectFromJSONString];
NSLog(@"json1.a:%@",[data1 objectForKey:@"a"]);
NSLog(@"json1.b:%@",[data1 objectForKey:@"b"]);

//如果json有嵌套，即value里有array、object，如果再使用objectFromJSONString，程序可能會報錯（測試結(jié)果表明：使用由網(wǎng)絡或得到的php/json_encode生成的json時會報錯，但使用NSString定義的json字符串時，解析成功），最好使用objectFromJSONStringWithParseOptions：
NSString *json2 = @"{\"a\":123, \"b\":\"abc\", \"c\":[456, \"hello\"], \"d\":{\"name\":\"張三\", \"age\":\"32\"}}";
NSLog(@"json2:%@", json2);

NSDictionary *data2 = [json2 objectFromJSONStringWithParseOptions:JKParseOptionLooseUnicode];
NSLog(@"json2.c:%@", [data2 objectForKey:@"c"]);
NSLog(@"json2.d:%@", [data2 objectForKey:@"d"]);