tabindex
How to tell apart tabindex not set vs -1.
by David Iglesias
HTML
<div id="byattr" tabindex="-1">
attribute
</div>
<div id="byprop">
property
</div>
<div id="notset">
notset
</div>
JavaScript
byprop.tabIndex = -1;
console.log(byattr.hasAttribute('tabindex')); // true
console.log(byprop.hasAttribute('tabindex')); // true
console.log(notset.hasAttribute('tabindex')); // false
console.log(byattr.getAttribute('tabindex')); // -1
console.log(byprop.getAttribute('tabindex')); // -1
console.log(notset.getAttribute('tabindex')); // null