将值传递给Javascript函数

Question

I'm calling a jQuery function, but the alert function displays [object Object]. The check value works, but not the passed id value.

Here's the call to the function taken from the html output:

<td class="myGroups">
    <input class="chkSubscribed" type="checkbox" onclick="UpdateSubscription(2)" name="subscribed">
</td>

Here's the javascsript function:

$(".chkSubscribed").change(function(id) {
    alert(id);
    var chkd=0;
    var groupid=id;
    if (this.checked) { chkd=1; }
        $.ajax({
        type:"POST",
        url:"resources/updateSubscribe.php",
        data: { group_id: groupid, checkval: chkd },
        success: function(){
        alert("Account updated!" + "chkval=" + chkd + " id=" + groupid);                }
    });
});

Thanks for any help!

Answer 1

There are a few different issues at play here.

1. Using alert() for debugging. This is almost always worse than using console.log() . Everything passed to alert is converted to a string, which is why you see "[object Object]" instead of something useful. Switch to console.log() and you'll see something meaningful.
2. jQuery event callbacks are passed a jQuery event object . That object is what id is set to.
3. The inline onclick handler has absolutely nothing to do with the change handler that you've bound with jQuery.

Answer 2

You're doing it wrong.

Either you want to call a function or you want to use the change event.

If you want to call a function create a function as follows:

function moo(id) {
    //code here
}

If you want to do it using the change event you can give your input an id of the number you want as follows:

<input id="2" class="chkSubscribed" type="checkbox" name="subscribed">

And then your javascript should look as follows:

$(".chkSubscribed").change(function() {
    id=this.id;
    //and the rest of the code as you wrote
});

Answer 3

jQuery函数change()将传递事件对象，而不是更改后的对象的ID-您将其视为当前的ID。