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Per example below...Looping through an object from a parsed JSON string returns an error "Object doesn't support this property or method". Could anyone advise how to make this work? Much appreciated (I spent 6 hours looking for an answer before asking here).

Function to parse JSON string into object (this works OK).

Function jsonDecode(jsonString As Variant) Set sc = CreateObject("ScriptControl"): sc.Language = "JScript" Set jsonDecode = sc.Eval("(" + jsonString + ")") End Function

Looping through the parsed object returns error "Object doesn't support this property or method".

Sub TestJsonParsing() Dim arr As Object 'Parse the json array into here Dim jsonString As String 'This works fine jsonString = "{'key1':'value1','key2':'value2'}" Set arr = jsonDecode(jsonString) MsgBox arr.key1 'Works (as long as I know the key name) 'But this loop doesn't work - what am I doing wrong? For Each keyName In arr.keys 'Excel errors out here "Object doesn't support this property or method" MsgBox "keyName=" & keyName MsgBox "keyValue=" & arr(keyName) Next End Sub

PS. I looked into these libraries already:

-vba-json Wasn't able to get the example working.
-VBJSON There's no vba script included (this might work but don't know how to load it into Excel and there is minimum documentation).

Also, Is it possible to access Multidimensional parsed JSON arrays? Just getting a basic key/value array loop working would be great (sorry if asking too much). Thanks.

Edit: Here are two working examples using the vba-json library. The question above is still a mystery though...

Sub TestJsonDecode() 'This works, uses vba-json library Dim lib As New JSONLib 'Instantiate JSON class object Dim jsonParsedObj As Object 'Not needed jsonString = "{'key1':'val1','key2':'val2'}" Set jsonParsedObj = lib.parse(CStr(jsonString)) For Each keyName In jsonParsedObj.keys MsgBox "Keyname=" & keyName & "//Value=" & jsonParsedObj(keyName) Next Set jsonParsedObj = Nothing Set lib = Nothing End Sub Sub TestJsonEncode() 'This works, uses vba-json library Dim lib As New JSONLib 'Instantiate JSON class object Set arr = CreateObject("Scripting.Dictionary") arr("key1") = "val1" arr("key2") = "val2" MsgBox lib.toString(arr) End Sub
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    Fyi: Got function code from here: tech.groups.yahoo.com/group/json/message/972 (don't have enough karma to put another link in the question). Commented Apr 24, 2011 at 22:59
  • Fyi: This Japanese user wrote a good piece on the issue: translate.google.com/… Commented Apr 24, 2011 at 23:01
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    Your first example doesn't work because "arr" is a native js object and it doesn't have "keys". Other libraries parse json directly to a dictionary (possibly with other nested dictionaries). That's why your second example works: you're iterating over the dictionary's keys. Commented Apr 25, 2011 at 3:56
  • @randyr I found this information to be inaccurate: objJSON ["key"]. When I tried that syntax, the VBA editor kept changing it to Debug.Print arr; ["key"] and inserting a semicolon. Commented Oct 24, 2013 at 16:19
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    I've just written a couple of VBA files that lets you parse JSON very easily - see github.com/mlocati/vba-json Commented Jan 26, 2022 at 16:39

6 Answers 6

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The JScriptTypeInfo object is a bit unfortunate: it contains all the relevant information (as you can see in the Watch window) but it seems impossible to get at it with VBA.

If the JScriptTypeInfo instance refers to a Javascript object, For Each ... Next won't work. However, it does work if it refers to a Javascript array (see GetKeys function below).

So the workaround is to again use the Javascript engine to get at the information we cannot with VBA. First of all, there is a function to get the keys of a Javascript object.

Once you know the keys, the next problem is to access the properties. VBA won't help either if the name of the key is only known at run-time. So there are two methods to access a property of the object, one for values and the other one for objects and arrays.

Option Explicit Private ScriptEngine As ScriptControl Public Sub InitScriptEngine() Set ScriptEngine = New ScriptControl ScriptEngine.Language = "JScript" ScriptEngine.AddCode "function getProperty(jsonObj, propertyName) { return jsonObj[propertyName]; } " ScriptEngine.AddCode "function getKeys(jsonObj) { var keys = new Array(); for (var i in jsonObj) { keys.push(i); } return keys; } " End Sub Public Function DecodeJsonString(ByVal JsonString As String) Set DecodeJsonString = ScriptEngine.Eval("(" + JsonString + ")") End Function Public Function GetProperty(ByVal JsonObject As Object, ByVal propertyName As String) As Variant GetProperty = ScriptEngine.Run("getProperty", JsonObject, propertyName) End Function Public Function GetObjectProperty(ByVal JsonObject As Object, ByVal propertyName As String) As Object Set GetObjectProperty = ScriptEngine.Run("getProperty", JsonObject, propertyName) End Function Public Function GetKeys(ByVal JsonObject As Object) As String() Dim Length As Integer Dim KeysArray() As String Dim KeysObject As Object Dim Index As Integer Dim Key As Variant Set KeysObject = ScriptEngine.Run("getKeys", JsonObject) Length = GetProperty(KeysObject, "length") ReDim KeysArray(Length - 1) Index = 0 For Each Key In KeysObject KeysArray(Index) = Key Index = Index + 1 Next GetKeys = KeysArray End Function Public Sub TestJsonAccess() Dim JsonString As String Dim JsonObject As Object Dim Keys() As String Dim Value As Variant Dim j As Variant InitScriptEngine JsonString = "{""key1"": ""val1"", ""key2"": { ""key3"": ""val3"" } }" Set JsonObject = DecodeJsonString(CStr(JsonString)) Keys = GetKeys(JsonObject) Value = GetProperty(JsonObject, "key1") Set Value = GetObjectProperty(JsonObject, "key2") End Sub

Note:

  • The code uses early binding. So you have to add a reference to "Microsoft Script Control 1.0".
  • You have to call InitScriptEngine once before using the other functions to do some basic initialization.
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Codo thanks - answered. This will set me on the right path. I'll let Bastan know also (he has a linked question to this).
@Codo Thanks, please tell me if we have some inbuilt libraries now.
Note that the above approach makes the system vulnerable in some cases, since it allows the direct access to the drives (and other stuff) for the malicious JS code via ActiveX's. Let's suppose you are parsing web server response JSON, like JsonString = "{a:(function(){(new ActiveXObject('Scripting.FileSystemObject')).CreateTextFile('C:\\Test.txt')})()}". After evaluating it you'll find new created file C:\Test.txt. So JSON parsing with ScriptControl ActiveX is not a good idea. Check the update of my answer for the RegEx-based JSON parser.
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Codo's answer is great and forms the backbone of a solution.

However, did you know VBA's CallByName gets you pretty far in querying a JSON structure. I've just written a solution over at Google Places Details to Excel with VBA for an example.

Actually just rewritten it without managing to use the functions adding to ScriptEngine as per this example. I achieved looping through an array with CallByName only.

So some sample code to illustrate

'Microsoft Script Control 1.0; {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx Option Explicit Sub TestJSONParsingWithVBACallByName() Dim oScriptEngine As ScriptControl Set oScriptEngine = New ScriptControl oScriptEngine.Language = "JScript" Dim jsonString As String jsonString = "{'key1':'value1','key2':'value2'}" Dim objJSON As Object Set objJSON = oScriptEngine.Eval("(" + jsonString + ")") Debug.Assert VBA.CallByName(objJSON, "key1", VbGet) = "value1" Debug.Assert VBA.CallByName(objJSON, "key2", VbGet) = "value2" Dim jsonStringArray As String jsonStringArray = "[ 1234, 4567]" Dim objJSONArray As Object Set objJSONArray = oScriptEngine.Eval("(" + jsonStringArray + ")") Debug.Assert VBA.CallByName(objJSONArray, "length", VbGet) = "2" Debug.Assert VBA.CallByName(objJSONArray, "0", VbGet) = "1234" Debug.Assert VBA.CallByName(objJSONArray, "1", VbGet) = "4567" Stop End Sub

And it does sub-objects (nested objects) as well see Google Maps example at Google Places Details to Excel with VBA

EDIT: Don't use Eval, try to parse JSON safer, see this blog post

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Super Simple answer - through the power of OO (or is it javascript ;) You can add the item(n) method you always wanted!

my full answer here

Private ScriptEngine As ScriptControl Public Sub InitScriptEngine() Set ScriptEngine = New ScriptControl ScriptEngine.Language = "JScript" ScriptEngine.AddCode "Object.prototype.myitem=function( i ) { return this[i] } ; " Set foo = ScriptEngine.Eval("(" + "[ 1234, 2345 ]" + ")") ' JSON array Debug.Print foo.myitem(1) ' method case sensitive! Set foo = ScriptEngine.Eval("(" + "{ ""key1"":23 , ""key2"":2345 }" + ")") ' JSON key value Debug.Print foo.myitem("key1") ' WTF End Sub
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This did not work. sc.AddCode "Object.prototype.get=function( i ) { return this[i]; };" ... Debug.Print arr.get("key") ... Error: Method 'get' of object 'JScriptTypeInfo' failed.
For anyone having issues with VBE or just not wanting to use it, I use Sub JSON() Dim o As Object Set o = CreateObject("ScriptControl") o.Language = "JScript" Dim output As String output = o.Eval("(" + "{""bob"":""Bobs Name"",""jim"":[1,2,3,4,5]}" + ")").bob MsgBox output End Sub
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As Json is nothing but strings so it can easily be handled if we can manipulate it the right way, no matter how complex the structure is. I don't think it is necessary to use any external library or converter to do the trick. Here is an example where I've parsed json data using string manipulation.

Sub Json_data() Const URL = "https://api.redmart.com/v1.5.8/catalog/search?extent=2&pageSize=6&sort=1&category=bakery" Dim http As New XMLHTTP60, html As New HTMLDocument Dim str As Variant With http .Open "GET", URL, False .send str = Split(.responseText, "category_tags"":") End With On Error Resume Next y = UBound(str) For i = 1 To y Cells(i, 1) = Split(Split(str(i), "title"":""")(1), """")(0) Cells(i, 2) = Split(Split(str(i), "sku"":""")(1), """")(0) Cells(i, 3) = Split(Split(str(i), "price"":")(1), ",")(0) Cells(i, 4) = Split(Split(str(i), "desc"":""")(1), """")(0) Next i End Sub
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So its 2020 and yet due to lack of an end-to-end solution, I stumbled upon this thread. It did help but if we need to access the data without Keys at runtime dynamically, the answers above, still need a few more tweaks to get the desired data.

I finally came up with a function to have an end-to-end neat solution to this JSON parsing problem in VBA. What this function does is, it takes a JSON string(nested to any level) as input and returns a formatted 2-dimensional array. This array could further easily be moved to Worksheet by plain i/j loops or could be played around conveniently due to its easy index-based accessibility.

Sample input-output

The function is saved in a JSON2Array.bas file at my Github repo. JSON2Array-VB

A demo usage subroutine is also included in the .bas file. Please download and import the file in your VBA modules. I hope it helps.

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While the Script Control is cool, it comes with lots of problems, especially with 64-bit VBA. My solution avoids the Script Control and works no matter how complex the JSON is.
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I know it's late, but for those who doesn't know how to use VBJSON, you just have to:

1) Import JSON.bas into your project (Open VBA Editor, Alt + F11; File > Import File)

2) Add Dictionary reference/class For Windows-only, include a reference to "Microsoft Scripting Runtime"

You can also use the VBA-JSON the same way, which is specific for VBA instead of VB6 and has all the documentation.

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