7 years later update: This is terrible advice. Please don't do this.
If you just need to pass variables from PHP to the javascript, you can have a tag in the php/html file using the javascript to begin with.
<script type="text/javascript">
var phpVars = <?php echo json_encode($vars) ?>;
</script>
<script type="text/javascript" src="yourScriptThatUsesPHPVars.js"></script>
If you're trying to call functions, then you can do this like this
<script type="text/javascript" src="YourFunctions.js"></script>
<script type="text/javascript">
// assume each element of $arrayWithVars has already been json_encoded
functionOne(<?php echo implode(', ', $arrayWithVars); ?>);
functionTwo(<?php echo json_encode($moreVars) ?>, <?php echo json_encode($evenMoreVars) ?>);
</script>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…