The HTMLSelectElement.type read-only property returns the form control's type.
One of the following:
"select-multiple" if multiple values can be selected."select-one" if only one value can be selected.switch (select.type) {
case "select-multiple":
// Multiple values may be selected
break;
case "select-one":
// Only one value may be selected
break;
default:
// Non-standard value (or this isn't a SELECT element)
}<select> HTML element, implementing this interface.