Recently I was looking at the source code implementation of some libraries, and I discovered that this was passed into the second parameter of addEventListener. I felt confused, so I came up to ask questions. The following code is what I simply simplified and passed the test

    <script>
        this.onclick=function(){
            console.log('onclick');
        }
        app.addEventListener('click',this);
    </script>

Why can events be bound in this way?