Boolean
Boolean (type:'boolean')
Survey.Survey.cssType = "bootstrap";
Survey.defaultBootstrapCss.navigationButton = "btn btn-green";

var json = { questions: [
  {
    "type": "boolean",
    "name": "bool",
    "title": "Please answer the question",
    "label": "Are you 21 or older?",
    "isRequired": true
  }
]};

window.survey = new Survey.Model(json);


survey.onComplete.add(function(result) {
    document.querySelector('#surveyResult').innerHTML = "result: " + JSON.stringify(result.data);
});


$("#surveyElement").Survey({ 
    model: survey 
});

<!DOCTYPE html>
<html>
<head>
    <title>Boolean (type:&#39;boolean&#39;) for plaform jQuery, SurveyJS Library Example</title>
    <script src="https://unpkg.com/jquery"></script>
<script src="/bundles/prettydiff?v=E3KTA7j8SjgR8NaAhm1jADBJxbWj5Yx1GQ2EdHBzuxE1"></script>

    <script src="https://surveyjs.azureedge.net/0.98.1/survey.jquery.js"></script>
  
    <link rel="stylesheet" href="https://unpkg.com/bootstrap@3.3.7/dist/css/bootstrap.min.css">
    <link rel="stylesheet" href="./index.css">

</head>
<body>
                <div id="surveyElement">
            </div>
    <div id="surveyResult"></div>

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

</body>
</html>
.btn-green {
  background-color: #1ab394;
  color: #fff;
  border-radius: 3px;
}
.btn-green:hover, .btn-green:focus {
    background-color: #18a689;
    color: #fff;
}
.panel-footer {
    padding: 0 15px;
    border:none;
    text-align: right;
    background-color: #fff;
}

defaultValue: (default is 'indeterminate'). The value showed by default.

var q = survey.getQuestionByName('bool');
q.defaultValue = yourvalue; 
//restart the survey
survey.clear();

var q = survey.getQuestionByName('bool');
q.showTitle = yourvalue; 
survey.render();

valueTrue

var q = survey.getQuestionByName('bool');
q.valueTrue = yourvalue; 
survey.render();

valueFalse

var q = survey.getQuestionByName('bool');
q.valueFalse = yourvalue; 
survey.render();