I'm wallowing in ES2015+ luxury with a few projects right now and am wondering whether I can get rid of the much hated crutch to check for undefined in the new wonderland.

Is there a shorter but still exact way to typeof varName === 'undefined' in ES2015+ already?

Of course I could use default parameters but this also feels like an unnecessary assignment.

function coolFn(a = null){

   if (a===null) console.log(no a supplied);

}