Why does global not work in functions?

Question

<!DOCTYPE html><html><head><meta charset="utf-8"><title>php.cn</title></head><body><?php$x=5;$y=6;function test(){	global $x,$y;	$y=$x+$y;}

明日边缘 · Answer

You only used the value of the global variable in the method, and the value of the global variable did not change.

失去过去 · Answer

Use the $GLOBAL super global function to print the data and you will know how much the data is

过客 · Answer

//是可以正常显示11呀，不行你复制本地测试一下看看
$x=5;
$y=6;
function test(){
global $x,$y;
$y=$x+$y;   //11= 5 + 6
}
test();
echo $x;	//5
echo "
";
echo $y;	//11

Php8, I'm coming too