jquery returns 0 when reading a negative from value in IE_问答_开发者

jquery returns 0 when reading a negative from value in IE

开发者 https://www.devze.com 2023-02-10 04:45 出处：网络

I\'m new to jQuery, and stumbled across some unexpected results today.When selecting the value from an LI element using jquery, IE will return a 0 if the value is negative instead of the correct value

I'm new to jQuery, and stumbled across some unexpected results today. When selecting the value from an LI element using jquery, IE will return a 0 if the value is negative instead of the correct value. In Chrome, the code below will throw up an alert with a -1, but in IE it says 0. Any thoughts?

<html>
    <head>    
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js" type="text/javascript"></script>  
    </head>
    <body>
    <script>
        $开发者_JS百科(function () {
            $(".ui-selected", this).each(function () {
                alert(this.value);      
            });
        });
   </script>

    <ol>
        <li class="ui-selected" value="-1" />
    </ol>

    </body>
</html>

Not sure about the reason, however value is not an attribute of list item elements. If you need a custom value use a data-value attribute (or other).

See this example for more information jsfiddle

<ul>
    <li value="-1" data-value="-1"></li>
</ul>

$('li').each(function(){
    alert(this.value); // 0
    alert($(this).attr('data-value')); // -1
})

You're not really using jQuery to get the value. I don't know why IE is behaving that way, but I'd say give it a try using ~~.attr(), or~~ the native getAttribute to get the value.

~~alert( $(this).attr('value') );~~

alert( this.getAttribute('value') );

@Josiah Ruddell noted that .attr() didn't work.

EDIT: don't use 'value' use any other attribute name. See the updated working example here

Even if "value" isn't a valid HTML attribute jQuery doesn't recognize this and its attribute selectors work just fine.

There isn't such a thing as an invalid selector. It either returns something or doesn't.

<ul>
    <li  class="ui-selected" myVar="-1" >
        Hi
    </li>
</ul>



$(".ui-selected").each(function(){
    var liValue =  $(this).attr('myVar');
    var intVal = parseInt(liValue); 
    // Just to be safe you've retrieved only an integer!

    alert(liValue);
});