VB.NET

Get the Index of a JSON Member

See more JSON Examples

This example demonstrates how to get the index of a given member by name.

{
  "name": "donut",
  "image":
    {
    "fname": "donut.jpg",
    "w": 200,
    "h": 200
    },
  "thumbnail":
    {
    "fname": "donutThumb.jpg",
    "w": 32,
    "h": 32
    }
}

VB.NET

Dim success As Boolean = False

Dim json As New Chilkat.JsonObject

' This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
' The presence of whitespace chars for pretty-printing makes no difference to the Load
' method. 
Dim jsonStr As String = "{""name"": ""donut"",""image"":{""fname"": ""donut.jpg"",""w"": 200,""h"": 200},""thumbnail"":{""fname"": ""donutThumb.jpg"",""w"": 32,""h"": 32}}"

success = json.Load(jsonStr)
If (success = False) Then
    Debug.WriteLine(json.LastErrorText)
    Exit Sub
End If


' The top-level JSON object has three members: name, image, and thumbnail.
Dim nameIndex As Integer = json.IndexOf("name")
' The index of the "name" member is 0.
Debug.WriteLine("nameIndex = " & nameIndex)

Dim thumbIndex As Integer = json.IndexOf("thumbnail")
' The index of the "thumbnail" member is 2.
Debug.WriteLine("thumbIndex = " & thumbIndex)

' The "fname" member is NOT a direct member of the top-level JSON object.
' It is a member of a nested object.  If we try to get the index of this
' member using the top-level JSON object, it is not found (and returns -1).
Dim fnameIndex As Integer = json.IndexOf("fname")
' The fnameIndex is -1 (not found).  This is correct.
Debug.WriteLine("fnameIndex = " & fnameIndex)

' Get the "image" object.
Dim imageObj As New Chilkat.JsonObject
json.ObjectOf2("image",imageObj)

' Now we can get the index of the "fname" object, because it is a direct
' member of the "image" object:
fnameIndex = imageObj.IndexOf("fname")
Debug.WriteLine("fnameIndex = " & fnameIndex)