What does it mean when I get a strict violation when using the this keyword in javascript?

Question

Can someone give me advice with this. I just started using jslint and I got an error message "strict violation" pointing to the line with "dialog(this)" -

function accessLinkClick(e) {
    e.preventDefault();
    $('.accessLink')
    .unbind('click', accessLinkClick);
    dialog(this);
}

function accessControls() {
    $('.accessLink')
        .bind('click', accessLinkClick);
    $('#logoutLink')
        .click(function (e) {
            window.location = $(this).attr('data-href');
        });
}

I never saw this message before. what does it mean?

See also http://stackoverflow.com/questions/6300937/strict-violation-using-this-keyword-and-revealing-module-pattern — Michael Berkowski, Sep 26 '12 at 13:55
why do you pass `this` do the `dialog()` function? `this` in that case refers to the global object (window) so you don't really need to pass it — Vlad Balmos, Sep 26 '12 at 13:55
Or http://stackoverflow.com/questions/2500512/jslint-why-do-this-code-result-in-a-strict-violation-error-message — CaffGeek, Sep 26 '12 at 13:56
This post should help: [http://stackoverflow.com/questions/1335851/what-does-use-strict-do-in-javascript-and-what-is-the-reasoning-behind-it][1] [1]: http://stackoverflow.com/questions/1335851/what-does-use-strict-do-in-javascript-and-what-is-the-reasoning-behind-it — Matt Asbury, Sep 26 '12 at 13:57
I don't get that message. Do you get it in your browsers error log? — javascript is future, Sep 26 '12 at 13:57
@javascriptisfuture the message is received while validating the code with [jslint](http://www.jslint.com/) — Vlad Balmos, Sep 26 '12 at 13:59
@javascriptisfuture, the OP is likely using "use strict", see: http://www.yuiblog.com/blog/2010/12/14/strict-mode-is-coming-to-town/ — CaffGeek, Sep 26 '12 at 14:00
@VladBalmos keep in mind that he uses `accessControls` as an eventHandler: `.bind('click', accessLinkClick)`. So `this` will be the element that fired the event. — Dennis, Sep 26 '12 at 14:12
Yes I am using strict mode. Dialog is a function that I have created. It opens a modal window. I need to pass it the information from the object that was clicked as that has data- attributes that are used when making the dialog. — Alan2, Sep 26 '12 at 14:38

Paul Sweatte · Answer 1 · 2017-07-26T15:07:17.980

Annex C of the spec explains it as such:

If this is evaluated within strict mode code, then the this value is not coerced to an object. A this value of null or undefined is not converted to the global object and primitive values are not converted to wrapper objects. The this value passed via a function call (including calls made using Function.prototype.apply and Function.prototype.call) do not coerce the passed this value to an object (10.4.3, 11.1.1, 15.3.4.3, 15.3.4.4).

Use e.target instead of this in the aforementioned code.

References

Annotated ES5: Annex C

What does it mean when I get a strict violation when using the this keyword in javascript?

1 Answers1