I wrote a PHP global variable in the view of thinkPHP3.2.3, and I made an amazing discovery.

Question

Using the thinkPHP3.2.3 framework, I wrote a very simple code in the view. The suffix of this view file is .html

<?php
    $x=10;
    $y=10;
    function add(){
        global $x,$y;
        $y=$x+$y;
    }
    add();
    echo $y;
?>

The echo result is 10. I don’t understand it. The result should be 20. I just wrote it again if I didn’t believe it, and it was still 10. I thought about it and wrote it into a separate php file, and the result was 20. Why is this? Do the views in thinkPHP not support PHP syntax? Please give me some advice!

Answer 1

Obviously the $x, $y here are not global variables.
So the global $x, $y in the function do not refer to the x, y above

If you look at the compiled template file, you will find that this code should be included in a function.

Answer 2

Try it

<?php
    $x=10;
    $y=10;
    function add() use(&$x, &$y){
        $y=$x+$y;
    }
    add();
    echo $y;
?>