Need help with increment decrement operators.

Question

https://code.sololearn.com/WTgYOrroRatl/?ref=app

Answer 1

<script>

var quantityVar = 0;
var textQuan = "Quantity:";

function quantity(){

quantityVar++;
document.getElementById("print").innerHTML = textQuan +" "+quantityVar;

}

function minus(){

quantityVar--;
document.getElementById("print").innerHTML =
textQuan +" "+quantityVar ;

}

</script>

Answer 2

Thanks!