js判断浏览器是否支持pdf

function isPDFSupported() {
    var iframe = document.createElement('iframe');
    iframe.style.display = 'none';
    document.body.appendChild(iframe);
    var isSupported = ('src' in iframe && 'contentDocument' in iframe && iframe.contentDocument.readyState === 'complete') ||
                      ('document' in iframe && iframe.document.readyState === 'complete');
    document.body.removeChild(iframe);
    return isSupported;
}

if (isPDFSupported()) {
    console.log('浏览器支持PDF');
} else {
    console.log('浏览器不支持PDF');
}

<script src="https://mozilla.github.io/pdf.js/build/pdf.js"></script>

PDFJS.GlobalWorkerOptions.workerSrc = 'https://mozilla.github.io/pdf.js/build/pdf.worker.js';

function checkPDFSupport() {
    var loadingTask = PDFJS.getDocument('path_to_pdf_file.pdf');
    loadingTask.promise.then(function(pdf) {
        console.log('浏览器支持PDF');
    }, function(error) {
        console.error('浏览器不支持PDF', error);
    });
}

checkPDFSupport();