How to pass value from php to Javascript variable on the code example

Example 1: javascript php variable

<script type="text/javascript">
   var php_var = "<?php echo $php_var; ?>";
</script>

Example 2: how to get a variable from php to javascript

<script type="text/javascript">
// boolean outputs "" if false, "1" if true
var bool = "<?php echo $bool ?>"; 

// numeric value, both with and without quotes
var num = <?php echo $num ?>; // 7
var str_num = "<?php echo $num ?>"; // "7" (a string)

var str = "<?php echo $str ?>"; // "A string here"
</script>