PHP code can be written directly in JavaScript

First, embed PHP code in javascript

If JavaScript is included in the JS file, then the JS file can also write directly PHP code, except that the JS file is the extension to be converted to PHP, such as:

<script herf= "js/demo.js.php" ></script>

Default values for JavaScript function parameters
You can set the default parameters in C language by doing this:

void foo (int a, int b = 1, bool c = false);

But JavaScript can't do this:
Newgame:function (A, b = 0)

IE and chrome will make an error, and FF will ignore it directly.
We can do this with a arguments read-only variable array:

function Newgame () {
var a = Arguments[0]? Arguments[0]: 1;
var B = arguments[1]? ARGUMENTS[1]: false;
function content
}