jquery selectedIndex doesn't work

问题

i have a from with many select tags , when the user submit the form i want to check if the user choose one option for all the select tags and this is my jquery code

$('#apForm select').each(function(){
            var $this = $(this);
            if ($this.selectedIndex == 0){
                var error = 'fill this please' ;
                $this.next('span').text(error);
                errorCount = errorCount + 1;   
            }
        });

and i tried like this

$this.attr("selectedIndex")

i just give you the piece of my code where my question is if i should give more code tell me

thank you for help

回答1:

var $this = $(this);
if($this.get(0).selectedIndex == 0) {

}

or just simple

this.selectedIndex; // not $this / $(this)

If no option it will return -1

here I showed all above cases

回答2:

It's this.selectedIndex, not $this.selectedIndex :)

• this is the HTMLDomElement
• $this is jQuery object

回答3:

If you are using a version of jQuery above 1.6? then you can use

if ( $this.prop('selectedindex') == 0 ){ /* handle */ }

来源：https://stackoverflow.com/questions/10652063/jquery-selectedindex-doesnt-work