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VBScript Requires Chilkat v11.4.0+

Call a JavaScript Function Returning a Boolean

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Demonstrates how to call a JavaScript function that returns a boolean.

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VBScript
Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

'  This is the JavaScript function we'll call:

'  function isEven(number) {
'      return number % 2 === 0;
'  }

set sbScript = CreateObject("Chilkat.StringBuilder")
success = sbScript.Append("function isEven(number) { return number % 2 === 0; }")

set js = CreateObject("Chilkat.Js")

set result = CreateObject("Chilkat.JsonObject")
result.EmitCompact = 0

'  Call Eval to add the function to the context's global object
success = js.Eval(sbScript,result)
If (success = 0) Then
    '  Examine the result for an exception.
    outFile.WriteLine(result.Emit())

    '  Also examine the LastErrorText.
    outFile.WriteLine(js.LastErrorText)
    WScript.Quit
End If

'  ------------------------------------------------------------------------------
'  Call the function isEven(8)

set funcCall = CreateObject("Chilkat.JsonObject")

'  Create JSON specifying the function name and arguments

'  {
'    "name": "isEven",
'    "args": [ 8 ]
'  }

success = funcCall.UpdateString("name","isEven")
success = funcCall.UpdateInt("args[0]",8)

success = js.CallFunction(funcCall,result)
If (success = 0) Then
    '  Examine the result for an exception.
    outFile.WriteLine(result.Emit())

    '  Also examine the LastErrorText.
    outFile.WriteLine(js.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine(result.Emit())

'  Output:
'  {
'    "type": "bool",
'    "value": true
'  }

retval = result.BoolOf("value")
outFile.WriteLine(retval)

'  Output:
'  1

outFile.Close