如何在jquery中调用函数

Question

I have a function called monitoring() as in this fiddle . My question here is, if i would like to call that function, can I simply do this?

$('#status_table #monitor_'+rowID).change(monitoring(rowID));

My logic is that, when the status of the checkboxes( #monitor_'+rowID is the checkbox ID) are changed, the function will be called.

As i would like to find out whether the function is being called, i do an append as follow:

$('#test').append(fbType + fbNum);

But it does not show up anything for fbType and fbNum in the div #test. Can someone point to me how i should call the function or correct my mistakes in that code/logic?

Answer 1

change expects a reference to a function, whereas you're currently calling it and using its return value as the argument to change –not what you want, since it doesn't return a function.

One option is to create a function generator that takes the row ID and use the return value as the argument to change , roughly:

function createMonitor(rowId) {
    return function() {
        // Do something with rowId
    };
};

$('#status_table #monitor_'+rowID).change(createMonitor(rowID));

Without knowing where rowID is coming from it's difficult to know if this is the best approach.

Answer 2

Your current code will call the function monitoring and bind its return value as the event handler , which is probably not what you need.

You can instead do it like:

$('#status_table #monitor_'+rowID).change(function() {
    monitoring(rowID);
});

Answer 3

Ah the power of closures:

$('#status_table #monitor_'+rowID).change(function() { monitoring(rowID) });

There will be a little more to it than this, as you probably need to actually pass in rowID somewhere; looking at your fiddle, it seemed at first glance as though you'd want to have this snippet inside the function addText , where you calculate a rowID.

Corrected fiddle (with rowID being utilized): http://jsfiddle.net/EVW4S/

Seems like there are more problems with this code... One tip that might help in debugging: console.debug is useful (rather than using alert() or changing content)

Answer 4

Create a button somewhere to trigger the function then. You can have a better control over the function as well.