Yes, I wrote it. The {} prevents the code from evaluating to a value that the browser then would use as the new value for the DOM, overwriting the existing pag

Yes, I wrote it. The {} prevents the code from evaluating to a value that the browser then would use as the new value for the DOM, overwriting the existing page. Try bookmarking javascript:123 and see what happens when you click it. Bookmarklets are URLs, so a newline in the code would be urlencoded as %0A. So you could do: javascript:alert(1)%0Aalert(2) But I would prefer: javascript:alert(1);alert(2)