页面加载时从PHP调用javascript函数

Question

I'm attempting to call a javascript function from a PHP loop. The call passes an id from the PHP loop and then is supposed to set a class based on whether it finds the id in a cookie. At the moment I am simply getting:

ReferenceError: getFaveClass() is not defined

My code is the following -

?>
<script>getFaveClass(<?php echo $row->id; ?>);</script>
<?php

Is there something I am missing or a better way of doing this?

Answer 1

There's nothing wrong with what you have written (although personally I'd use json_encode to ensure the value is properly handled).

All the error means is that you haven't defined the getFaveClass function. If it's in an external .js file, make sure you're including it.

Answer 2

If the id is output, the data should be on the page when the script is executed. Echo-ing out PHP as initial data to a JavaScript call is fine. I suggest you check and see what is actually being output, rather than your PHP source, in order to debug JS errors.

Your problem is probably what happens if $row->id == "" .

Answer 3

Have you declared the function getFaveClass() and is there a value in the <?php echo $row->id; ?> <?php echo $row->id; ?>

Please check your function name to be exact including the case where you have been calling this.

Just check that it should run. AS i can't see anything wrong with your what so ever code you have shared.