Serialize and Deserialize Json and Json Array in Unity

Question

I have a list of items send from a PHP file to unity using WWW   The WWW text looks like                    playerId    1            playerLoc    Powai                        playerId    2            playerLoc    Andheri                        playerId    3            playerLoc    Churchgate            Where I trim the extra    from the string  When I try to parse it using Boomlagoon JSON  only the first object is retrieved  I found out that I have to deserialize   the list and have imported MiniJSON    But I am confused how to deserialize   this list  I want to loop through every JSON object and retrieve data  How can I do this in Unity using C    The class I am using is   public class player       public string playerId   get  set        public string playerLoc   get  set        public string playerNick   get  set        After trimming the    I am able to parse the json using MiniJSON  But it is returning only the first KeyValuePair    IDictionary lt string  object gt  players   Json Deserialize serviceData  as IDictionary lt string  object gt    foreach  KeyValuePair lt string  object gt  kvp in players        Debug Log string Format  Key    0   Value    1    kvp Key  kvp Value        Thanks

User · Answer

Don t trim the    and you should be fine     identify a JSON array which is exactly what you require to be able to iterate its elements

User · Answer

Unity  lt   2019 Narottam Goyal had a good idea of wrapping the array in a json object  and then deserializing into a struct  The following uses Generics to solve this for arrays of all type  as opposed to making a new class everytime   System Serializable  private struct JsonArrayWrapper lt T gt        public T wrap result     public static T ParseJsonArray lt T gt  string json        var temp   JsonUtility FromJson lt JsonArrayWrapper lt T gt  gt   quot    quot  wrap result  quot   quot    json    quot   quot        return temp wrap result     It can be used in the following way  string   options   ParseJsonArray lt string   gt  someArrayOfStringsJson    Unity 2020 In Unity 2020 there is an official newtonsoft package which is a far better json library

User · Answer

Unity added JsonUtility to their API after 5 3 3 Update  Forget about all the 3rd party libraries unless you are doing something more complicated  JsonUtility is faster than other Json libraries  Update to Unity 5 3 3 version or above then try the solution below   JsonUtility is a lightweight API  Only simple types are supported  It does not support collections such as Dictionary  One exception is List  It supports List and List array   If you need to serialize a Dictionary or do something other than simply serializing and deserializing simple datatypes  use a third-party API  Otherwise  continue reading   Example class to serialize    Serializable  public class Player       public string playerId      public string playerLoc      public string playerNick      1  ONE DATA OBJECT  NON-ARRAY JSON   Serializing Part A   Serialize to Json with the public static string ToJson object obj   method   Player playerInstance   new Player    playerInstance playerId    8484239823   playerInstance playerLoc    Powai   playerInstance playerNick    Random Nick      Convert to JSON string playerToJson   JsonUtility ToJson playerInstance   Debug Log playerToJson     Output     playerId   8484239823   playerLoc   Powai   playerNick   Random Nick       Serializing Part B   Serialize to Json with the public static string ToJson object obj  bool prettyPrint   method overload  Simply passing true to the JsonUtility ToJson function will format the data  Compare the output below to the output above   Player playerInstance   new Player    playerInstance playerId    8484239823   playerInstance playerLoc    Powai   playerInstance playerNick    Random Nick      Convert to JSON string playerToJson   JsonUtility ToJson playerInstance  true   Debug Log playerToJson     Output          playerId    8484239823        playerLoc    Powai        playerNick    Random Nick        Deserializing Part A   Deserialize json with the public static T FromJson string json   method overload   string jsonString       playerId     8484239823     playerLoc     Powai     playerNick     Random Nick      Player player   JsonUtility FromJson lt Player gt  jsonString   Debug Log player playerLoc     Deserializing Part B   Deserialize json with the public static object FromJson string json  Type type   method overload   string jsonString       playerId     8484239823     playerLoc     Powai     playerNick     Random Nick      Player player    Player JsonUtility FromJson jsonString  typeof Player    Debug Log player playerLoc       Deserializing Part C   Deserialize json with the public static void FromJsonOverwrite string json  object objectToOverwrite   method  When JsonUtility FromJsonOverwrite is used  no new instance of that Object you are deserializing to will be created  It will simply re-use the instance you pass in and overwrite its values   This is efficient and should be used if possible   Player playerInstance  void Start           Must create instance once     playerInstance   new Player        deserialize       void deserialize         string jsonString       playerId     8484239823     playerLoc     Powai     playerNick     Random Nick             Overwrite the values in the existing class instance  playerInstance   Less memory Allocation     JsonUtility FromJsonOverwrite jsonString  playerInstance       Debug Log playerInstance playerLoc         2  MULTIPLE DATA ARRAY JSON   Your Json contains multiple data objects  For example playerId appeared more than once  Unity s JsonUtility does not support array as it is still new but you can use a helper class from this person to get array working with JsonUtility   Create a class called JsonHelper  Copy the JsonHelper directly from below   public static class JsonHelper       public static T   FromJson lt T gt  string json                Wrapper lt T gt  wrapper   JsonUtility FromJson lt Wrapper lt T gt  gt  json           return wrapper Items             public static string ToJson lt T gt  T   array                Wrapper lt T gt  wrapper   new Wrapper lt T gt             wrapper Items   array          return JsonUtility ToJson wrapper              public static string ToJson lt T gt  T   array  bool prettyPrint                Wrapper lt T gt  wrapper   new Wrapper lt T gt             wrapper Items   array          return JsonUtility ToJson wrapper  prettyPrint               Serializable      private class Wrapper lt T gt                public T   Items            Serializing Json Array   Player   playerInstance   new Player 2    playerInstance 0    new Player    playerInstance 0  playerId    8484239823   playerInstance 0  playerLoc    Powai   playerInstance 0  playerNick    Random Nick    playerInstance 1    new Player    playerInstance 1  playerId    512343283   playerInstance 1  playerLoc    User2   playerInstance 1  playerNick    Rand Nick 2      Convert to JSON string playerToJson   JsonHelper ToJson playerInstance  true   Debug Log playerToJson     Output          Items                            playerId    8484239823                playerLoc    Powai                playerNick    Random Nick                                    playerId    512343283                playerLoc    User2                playerNick    Rand Nick 2                        Deserializing Json Array   string jsonString      r n      Items      r n          r n              playerId      8484239823    r n              playerLoc      Powai    r n              playerNick      Random Nick   r n           r n          r n              playerId      512343283    r n              playerLoc      User2    r n              playerNick      Rand Nick 2   r n          r n      r n     Player   player   JsonHelper FromJson lt Player gt  jsonString   Debug Log player 0  playerLoc   Debug Log player 1  playerLoc     Output      Powai      User2     If this is a Json array from the server and you did not create it by hand   You may have to Add   Items   in front of the received string then add   at the end of it   I made a simple function for this   string fixJson string value        value       Items       value            return value      then you can use it   string jsonString   fixJson yourJsonFromServer   Player   player   JsonHelper FromJson lt Player gt  jsonString       3 Deserialize json string without class  amp  amp  De-serializing Json with numeric properties  This is a Json that starts with a number or numeric properties   For example       USD      15m    1740 01   last    1740 01   buy    1740 01   sell    1744 74   symbol             ISK      15m    179479 11   last    179479 11   buy    179479 11   sell    179967   symbol     kr      NZD      15m    2522 84   last    2522 84   buy    2522 84   sell    2529 69   symbol             Unity s JsonUtility does not support this because the  15m  property starts with a number  A class variable cannot start with an integer   Download SimpleJSON cs from Unity s wiki   To get the  15m  property of USD   var N   JSON Parse yourJsonString   string price   N  USD    15m   Value  Debug Log price     To get the  15m  property of ISK   var N   JSON Parse yourJsonString   string price   N  ISK    15m   Value  Debug Log price     To get the  15m  property of NZD   var N   JSON Parse yourJsonString   string price   N  NZD    15m   Value  Debug Log price     The rest of the Json properties that doesn t start with a numeric digit can be handled by Unity s JsonUtility     4 TROUBLESHOOTING JsonUtility   Problems when serializing with JsonUtility ToJson   Getting empty string or        with JsonUtility ToJson   A  Make sure that the class is not an array  If it is  use the helper class above with JsonHelper ToJson instead of JsonUtility ToJson   B  Add  Serializable  to the top of the class you are serializing    C  Remove property from the class  For example  in the variable  public string playerId   get  set    remove   get  set     Unity cannot serialize this   Problems when deserializing with JsonUtility FromJson   A  If you get Null  make sure that the Json is not a Json array  If it is  use the helper class above with JsonHelper FromJson instead of JsonUtility FromJson   B  If you get NullReferenceException while deserializing  add  Serializable  to the top of the class   C Any other problems  verify that your json is valid  Go to this site here and paste the json  It should show you if the json is valid  It should also generate the proper class with the Json  Just make sure to remove  remove   get  set    from each variable and also add  Serializable  to the top of each  class generated     Newtonsoft Json   If for some reason Newtonsoft Json must be used then check out the forked version for Unity here  Note that you may experience crash if certain feature is used  Be careful     To answer your question   Your original data is      playerId   1   playerLoc   Powai     playerId   2   playerLoc   Andheri     playerId   3   playerLoc   Churchgate      Add   Items   in front of it then add   at the end of it    Code to do this   serviceData       Items       serviceData          Now you have      Items     playerId   1   playerLoc   Powai     playerId   2   playerLoc   Andheri     playerId   3   playerLoc   Churchgate       To serialize the multiple data from php as arrays  you can now do  public player   playerInstance  playerInstance   JsonHelper FromJson lt player gt  serviceData     playerInstance 0  is your first data  playerInstance 1  is your second data  playerInstance 2  is your third data  or data inside the class with playerInstance 0  playerLoc  playerInstance 1  playerLoc  playerInstance 2  playerLoc         You can use playerInstance Length to check the length before accessing it   NOTE   Remove   get  set    from the player class  If you have   get  set     it won t work  Unity s JsonUtility does NOT work with class members that are defined as properties

User · Answer

IF you are using Vector3 this is what i did   1- I create a class Name it Player   using System  using System Collections  using System Collections Generic  using UnityEngine   Serializable  public class Player       public Vector3   Position       2- then i call it like this   if    ispressed    true                        Player playerInstance   new Player                playerInstance Position   newPos              string jsonData   JsonUtility ToJson playerInstance                reference Child  Position    Random Range 0  1000000   SetRawJsonValueAsync jsonData               Debug Log jsonData                ispressed   false              3- and this is the result       Position        x  -2 8567452430725099  y  -2 4323320388793947  z  0 0

User · Answer

Assume you got a JSON like this                   type    qrcode            symbol                                    seq   0                   data    HelloWorld9887725216                    error   null                                   To parse the above JSON in unity  you can create JSON model like this    System Serializable  public class QrCodeResult       public QRCodeData   result      System Serializable  public class Symbol       public int seq      public string data      public string error      System Serializable  public class QRCodeData       public string type      public Symbol   symbol      And then simply parse in the following manner     var myObject   JsonUtility FromJson lt QrCodeResult gt      result       jsonString ToString             Now you can modify the JSON CODE according to your need  https   docs unity3d com Manual JSONSerialization html

User · Answer

To Read JSON File  refer this simple example  Your JSON File  StreamingAssets Player json          Name    MyName        Level   4     C  Script  public class Demo       public void ReadJSON                 string path   Application streamingAssetsPath     Player json           string JSONString   File ReadAllText path           Player player   JsonUtility FromJson lt Player gt  JSONString           Debug Log player Name             System Serializable  public class Player       public string Name      public int Level

User · Answer

You can use Newtonsoft Json just add Newtonsoft dll to your project and use below script  using System  using Newtonsoft Json  using UnityEngine   public class NewBehaviourScript   MonoBehaviour         Serializable      public class Person               public string id          public string name            public Person   person       private void Start                var myjson   JsonConvert SerializeObject person            print myjson                another solution is using JsonHelper  using System  using Newtonsoft Json  using UnityEngine   public class NewBehaviourScript   MonoBehaviour         Serializable      public class Person               public string id          public string name            public Person   person       private void Start                 var myjson   JsonHelper ToJson person            print myjson

User · Answer

Like  Maximiliangerhardt said  MiniJson do not have the capability to deserialize properly  I used JsonFx and works like a charm  Works with the     player   p   JsonReader Deserialize lt player   gt  serviceData   Debug Log p 0  playerId       p 0  playerLoc  --   p 1  playerId         p 1  playerLoc  --   p 2  playerId         p 2  playerLoc

User · Answer

you  have to add  System Serializable  to PlayerItem class  like this   using System   System Serializable  public class PlayerItem         public string playerId      public string playerLoc      public string playerNick

[c#] Serialize and Deserialize Json and Json Array in Unity

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