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v 1.9.51

Complex questions in expressions


                    var json = {
  "showQuestionNumbers": "off",
  "elements": [
      "type": "matrix",
      "name": "matrix",
      "title": "Please select the question you wish to answer",
      "columns": [
          "value": "yes",
          "text": "Yes, I do"
          "value": "no",
          "text": "Please do not ask this question"
      "rows": [
          "value": "name",
          "text": "Could you answer what is your name?"
          "value": "city",
          "text": "Could you tell us the city you have born?"
      "type": "text",
      "name": "name",
      "title": "What is your name?",
      "visibleIf": "{} = 'yes'"
      "type": "text",
      "name": "city",
      "title": "What is the city you have born?",
      "visibleIf": "{} = 'yes'"

                    window.survey = new SurveyKnockout.Survey(json);
            survey.onComplete.add(function(sender) {
            document.querySelector('#surveyResult').textContent =
            "Result JSON:\n" + JSON.stringify(, null, 3);

<!DOCTYPE html>
<html lang="en">
    <title>Complex questions in expressions, Knockoutjs Survey Library Example</title>
<meta name="viewport" content="width=device-width" />
    <script src=""></script>
    <script src="/DevBuilds/survey-core/survey.core.min.js"></script>
    <script src="/DevBuilds/survey-core/survey.i18n.min.js"></script>
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    <link href="/DevBuilds/survey-core/defaultV2.min.css" type="text/css" rel="stylesheet" />
    <link rel="stylesheet" href="./index.css">

<body style="margin: 0">
            <div id="surveyElement" style="display:inline-block;width:100%;">
    <div id="surveyResult"></div>

<script type="text/javascript" src="./index.js"></script>


You may use the typical question value, for example "text", in an expression as:

visibileIf: "{textQuestion} = 'Yes'"
For questions like Multiple Text, Matrix, Matrix Dropdown, Matrix Dynamic and Panel Dynamic you can't use the same approach.

Multiple Text, Matrix questions values are objects:
"name": { "firstName": "John", "lastName": "Snow"}
As result you may use it in expression as:
visibleIf: "{name.firstName} = 'John' and {name.lastName = 'Snow'}"

Matrix dropdown question is an object of objects:
"rateTeaches": { "math": { "knowSubject": 5, "explainsClearly": 4}, "literature": { "knowSubject": 4, "explainsClearly": 4} }
You may use it in expression as:
visibleIf: "{rateTeaches.math.explainsClearly} > 3}"

Matrix and Panel Dynamic questions are array of objects:
"rateTeaches": [{"subject": "math", "knowSubject": 5, "explainsClearly": 4}, {"subject": "literature",  "knowSubject": 4, "explainsClearly": 4} ]
The expression can be as:
visibleIf: "{rateTeaches[0].explainsClearly} > 3}"