Cannot use isUndefined on console object in IE8, will throw javascript error #280

butchmarshall · 2016-07-21T18:44:23Z

This code crashes IE8 - need to explicitly check typeof

…t error

tivie · 2016-07-22T02:01:47Z

Really? IE8 complains? Why?

butchmarshall · 2016-07-22T04:00:26Z

Basically, IE8 isn't a good browser.

<html>

<head>
    <script type="text/javascript">
        function isUndefined(a) {
            return typeof(a) === "undefined"
        }
        if (isUndefined(console)) {
            alert('yes!');
        }
        alert('no');
    </script>
</head>
<body>

</body>

</html>

Run that in IE8. An undefined variable will halt script execution and you'll never get "no".

The key is to never open the "developer tools" in IE8. If you do, it will work until you close and reopen the browser.

tivie · 2016-08-19T18:35:26Z

this is mental... But does this only happen with console object? or with any other variable?

butchmarshall added 2 commits July 21, 2016 18:43

Cannot use isUndefined on console object in IE8, will throw javascrip…

cb2761a

…t error

Fixed jslint tests

125bcc5

tivie self-assigned this Aug 19, 2016

tivie added the bug label Aug 19, 2016

tivie added this to the Improve IE8 compatibility milestone Aug 19, 2016

tivie closed this in 561dc5f Jan 9, 2017

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Cannot use isUndefined on console object in IE8, will throw javascript error #280

Cannot use isUndefined on console object in IE8, will throw javascript error #280

butchmarshall commented Jul 21, 2016

tivie commented Jul 22, 2016

butchmarshall commented Jul 22, 2016 •

edited

tivie commented Aug 19, 2016

Cannot use isUndefined on console object in IE8, will throw javascript error #280

Cannot use isUndefined on console object in IE8, will throw javascript error #280

Conversation

butchmarshall commented Jul 21, 2016

tivie commented Jul 22, 2016

butchmarshall commented Jul 22, 2016 • edited

tivie commented Aug 19, 2016

butchmarshall commented Jul 22, 2016 •

edited