PHP声明变量

$count = 100;

$count = $count + $count;

echo $count;

echo "<br/>";

echo "echo "

global $num;

$num = $num + $num ;

echo $num ;

$GLOBALS['num'] =$GLOBALS['num']+$GLOBALS['num']echo "

该值是：200

 

在使用全局变量时，一定要注意，因为使用全局变量很容易发生意外。

static $num =0;

$num ++;

echo "echo "<br/>";