can i write javascript in php file code example

Example 1: write in a file using php

<?php
$myfile = fopen("file_name.txt", "w") or die("Unable to open file!");
$txt = "Hello world\n";
fwrite($myfile, $txt);
$txt = " Php.\n";
fwrite($myfile, $txt);
fclose($myfile);
?>

Example 2: how to write php in script file

<script type="text/javascript" src="YourFunctions.js"></script>
<script type="text/javascript">
    functionOne(<?php echo implode(', ', $arrayWithVars); ?>);
    functionTwo(<?php echo $moreVars; ?>, <?php echo $evenMoreVars; ?>);
</script>