Parse Json string to Classic ASP page

As a quick solution for simple json structure and escaped values, this simple function returns the key values by splitting the json string on double quotes chr(34):

function getKeyValue(JsonString,key)
    myarray=split(JsonString,key,-1,1)
    if ubound(myarray)>0 then
        myarray2=split(myarray(1),chr(34),-1,1)
        getKeyValue=myarray2(2)
    else
        getKeyValue=""
    end if
end function

usage:

response.write("<li> date :" & getKeyValue(Your_Json_String_Here,"date") & "</li>")

Almost certain no-one will ever need this answer, but just in case.

Rather than rely on external libraries, or ScriptControlobjects, simply do it with some Server-Side JavaScript.

Set jsreader = New JsonReader
jsreader.loadJson(myJson)

adviser_id = jsreader.getElement("someField")

Using this VBScript module:

<%

class JsonReader

    private root

    private sub Class_Terminate()
        set root = nothing
    end sub

    public sub loadJson(sJson)
        set root = new_JsonEngine(sJson)
        if root.hasError() then err.Raise 10000, "JsonReader:loadJson", "Syntax Error"
    end sub

    public function getElement(sPath)
        getElement = root.getElement(sPath)
    end function

    public function getChildNodes(sPath)
        getChildNodes = split(root.getChildNodes(sPath), ",")
    end function

    public function elementExists(sElement)
        elementExists = root.elementExists(sElement)
    end function

end class

%>

<script language="javascript" runat="server" src="json2.js"></script>
<script language="javascript" runat="server">

function new_JsonEngine(sJson) {
    return new JsonEngine(sJson);
};

function JsonEngine(sJson) {
    var me = this;
    this.data = {};
    this.error = false;
    this.initialize = function(sJson) {
        try {
            this.data = JSON.parse(sJson);
        } catch (e) {
            me.error = true;
        }
    };

    this.elementExists = function (sElement) {
        var currentRoot = me.data;
        var aPath = sElement.split('.');
        var bExists  = true;
        for (var i = 0, len = aPath.length; i < len; i++) {
            currentRoot = currentRoot[aPath[i]];
            if (typeof currentRoot === "undefined") {
                bExists = false;
                break;
            }
        }

        return bExists;
    };

    this.getElement = function(sPath) {
        var node = me.data;
        var aPath = sPath.split('.');
        for(var i = 0, len = aPath.length; i < len; i++) {
            node = node[aPath[i]];
        }
        return (typeof node == "object" && node.length)? "[object Array]" : node;
    };
    this.getChildNodes = function(sPath) {
        var keys = [];
        var parentNode = me.data;
        if( sPath.length > 0 ) {
            var aPath = sPath.split('.');
            for(var i = 0, len = aPath.length; i < len; i++) {
                parentNode = parentNode[aPath[i]];
            }
        }
        for(var key in parentNode) {
            (sPath.length > 0)? keys.push(sPath + "." + key) : keys.push(key);
        }
        return keys;
    };
    this.hasError = function() {
        return me.error;
    };
    this.initialize(sJson);
}
</script>

' >>> A hundred times faster!

public function GetJsonObject( str_json )
    dim obj_script: Set obj_script = CreateObject("ScriptControl")
    obj_script.Language = "JScript"
    obj_script.Eval("var obj_json = " & str_json)
    set GetJsonObject = obj_script.Eval("obj_json")
end function

dim str_json: str_json = "{ date :'4/28/2017', custType: 100, vehicle: 1 }"
dim obj_json: set obj_json = GetJsonObject(str_json)

response.write("date :" & obj_json.date & "<br />")
response.write("custType :" & obj_json.custType & "<br />")
response.write("vehicle :" & obj_json.vehicle & "<br />")

' >>> no lib to include and when the JSON is very long, it works super fast also, not with lib "aspJSON". Plus fields can be read directly, no string like xxx("vehicle")

Honestly, for every reader as of today, the Chilkat Tools component is just excellent at this task, reliable and fast, as it is compiled as a COM+ component. I'm using it since 2016 without a glitch for all my works related to JSON and Classic ASP.

I'm using it on my own servers, as being specialized in Classic ASP hosting.
So if your hosting company offers it, go for this component ! It will greatly simplify things

Otherwise, yes the `aspJSON` class may be enough for simple JSON data structures (I used it in the past).