如何确定下拉列表是否有可供选择的选项？

Question

如何确定下拉列表是否有可供选择的选项？

Answer 1

var menu = getElementById("select_id");
if(menu.options.length) {
    // has children
} else {
    // empty
}

Answer 2

if ($("#myselect option").length > 0) {
  // Yay we have options
}

Answer 3

var hasOptions = !!$('#theSelect option').filter(function() { return !this.disabled; }).length;

maybe? This looks for <option> elements that are not disabled.

Answer 4

$('#input1 option').length > 0

其中#input是您正在运行此测试的select元素的ID。

Answer 5

if ($("#myselect option:enabled").length){
   // Yay!
}else{
   // Oh, no available options
}

http://api.jquery.com/enabled-selector/

Answer 6

Native javascript solution:

!!document.getElementById('jiveviewthreadsform-filter').children.length

(Please do not overuse jQuery, thanks)

Answer 7

Very hackily, you can just check its selectedIndex; since most browsers ensure that there is something selected if at all possible, it will only be -1 if there are no selectable options.